Interferometry with relativistic electrons
Open accessAbstract
We propose an experiment to test the influence of Lorentz contraction on the interference pattern of a beam of electrons. The electron beam is split and recombined by two pairs of bichromatic laser pulses, using a variation of the Kapitza-Dirac effect. Between the pairs, the electrons are accelerated to relativistic speed. We show that Lorentz contraction of the distance between two partial beams will then lead to a reduction of fringe visibility. The connection of the proposal to Bell's spaceship paradox is discussed.
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Written from the paper’s full text.
TL;DR
The paper proposes an electron interferometer in which two partial beams are split and recombined by bi-chromatic laser pulses via a Kapitza-Dirac effect, then accelerated to relativistic speed. Lorentz contraction causes the beams to miss each other by \(\Delta z(\gamma-1)\), reducing fringe visibility, and the setup is closely related to Bell’s spaceship paradox.
Key findings
- The proposed experiment uses two pairs of bi-chromatic laser pulses to split and recombine an electron beam; between the pairs the electrons are accelerated to relativistic speed \(v=\beta c\).
- Lorentz contraction of the beam separation \(\Delta z\) leads to a spatial mismatch \(\Delta z'-\Delta z=(\gamma-1)\Delta z\) in the electron rest frame, reducing fringe visibility.
- A numerical simulation with fourth-order harmonic generation (\(n=4\), \(\beta=3/5\)) gives a beam separation of about \(15\,\mu\text{m}\), using \(T=50\,\text{ns}\), \(T'=12.5\,\text{ns}\), and \(\tilde T=31\,\text{ns}\), with an electric potential difference of \(127.75\,\text{kV}\).
- The estimated photon-emission probability during acceleration is less than \(5\%\) for cutoff parameter \(u>10^{-4}\), so photon emission is not expected to pose a problem.
Methods
- Theoretical proposal and analysis based on the Dirac equation, extending a non-relativistic Ramsey-Bordé electron interferometer to the relativistic regime.
- Numerical simulation in momentum space using a 10,000-point grid for Fourier transformation; the last two laser pulses are treated by Lorentz transforming the wavefunction into the mean rest frame of beam B.
- The Kapitza-Dirac beam splitter is modeled by resonant coupling between momenta separated by \(2\hbar k_L\), with pulse duration \(t_L=\pi/(4g_1g_2)=1.56\,\text{ns}\).
Limitations
- The paper states that the analysis assumes a homogeneous electric field, laser pulses switched on and off at specific times, and a one-dimensional treatment that ignores forces in the \(x\)- and \(y\)-directions.
- The paper notes that the proposed experiment is not strictly an interference experiment: the measured quantity is a displacement between two partial beams, though fringe visibility can provide information about the displacement if the beams partially overlap.
- The beam splitting process is velocity-selective, so only electrons within a specific velocity range are split or recombined; this increases the number of experimental runs needed, and detection may require time-of-flight measurement or deceleration after the last laser pulse.
Model-written summary. Check it against the paper before relying on it.
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Claims the paper makes
2 of 17 cited sources checked · 1 supported · 0 flagged · accuracy not yet measured
- Premisecitation§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
Rule (iv) provides a reasonable approximation for the evolution of the electron state inside a bi-chromatic laser pulse if the resonance condition is fulfilled.
“It was shown in Ref. [13] that rule (iv) provides a reasonable approximation for the evolution of the electron state inside a bi-chromatic laser pulse if the resonance condition”
Quote in the paperSubstantial claim1 of 1 sources checked- cites [13] K.-P. Marzlin, Phys. Rev. A 88 , 043621 (2013), URL http://arxiv.org/abs/1307.4020 . source
In the Kapitza–Dirac beam-splitter discussion (page unavailable), the paper derives a simplified evolution for a resonant electron state and says Eq. (10) remains an excellent approximation under specified conditions. Resonance alone is not sufficient in its account: it also requires weak coupling and a sufficiently narrow momentum distribution. The copy does not identify the citing paper’s ‘rule (iv)’ by that name. (LLM, conf=0.83)
Experimental — accuracy not yet measured
- Findingreasoning§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
The Lorentz transformation of the vector potential results in the same form (19) except that the frequencies are replaced by ω~1=(1−β)γω1 and ω~2=(1+β)γω2.
“Consequently, the vector potential still has the form (19) except that in the exponentials we have to make the replacements ω 1 → ˜ ω 1 ≡ (1 -β ) γω 1 and ω 2 → ˜ ω 2 ≡ (1+ β ) γω 2 .”
Quote in the paperSubstantial claim- Rests on an assumption: Despite the relativistic mean electron velocity, the velocity spread of the electron beam is still non-relativistic.
- Findingreasoning§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
If the final electron velocity is β=(n−1)/(n+1), then the resonance condition can be fulfilled by choosing δω=∓2ħ√n k_22/m.
“If the final velocity of the electrons takes the value β = ( n -1) / ( n + 1) then these relations simplify to ∆˜ ω = √ nδω and ˜ k L ≈ √ nω 2 /c = √ nk 2 . The resonance condition can then easily be fulfilled by choosing δω = ∓ 2 ℏ √ nk 2 2 /m”
Quote in the paperSubstantial claim - Findingnone given§ VIII. CONCLUSION · p. 7
Two partial beams, which would be perfectly overlapping for non-relativistic electrons, will miss each other by an amount ∆z(γ-1), with ∆z the beam separation in the interferometer.
“Two partial beams, which would be perfectly overlapping for non-relativistic electrons, will miss each other by an amount ∆ z ( γ -1), with ∆ z the beam separation in the interferometer.”
Quote in the paperNot a substantial claim - Findingown data§ V. NUMERICAL RESULTS · p. 4
In the numerical simulation, the distance between wavepackets A and B is about 15 μm, corresponding to the spatial mismatch induced by Lorentz contraction.
“The distance between wavepackets A and B of about 15 µ m corresponds to the spatial mismatch induced by Lorentz contraction.”
Quote in the paperNot a substantial claim- Rests on an assumption: For the chosen pulse duration, the laser intensities are so low that coupling to other momenta is very weak and can be neglected except when the resonance condition is fulfilled.
- Findingnone given§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
The distance travelled by electrons during acceleration is c2(γ−1)/a.
“c 2 ( γ -1) /a corresponds to the distance travelled by the electrons during the acceleration phase.”
Quote in the paperNot a substantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
For γ=5/4 and acceleration 1.8×10^16 m/s2, corresponding to an electric field strength of 10^5 V/m, the distance travelled by electrons during acceleration is about 1.3 m.
“For γ = 5 / 4 and an acceleration of 1 . 8 × 10 16 m/s 2 , which corresponds to an electric field strength of 10 5 V/m, this distance is about 1.3 m.”
Quote in the paperNot a substantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
The final mean positions of the two partial beams in the lab frame agree with relativistic trajectories of classical point particles.
“These mean positions agree with relativistic trajectories of classical point particles in the lab frame.”
Quote in the paperSubstantial claim- Rests on an assumption: The momentum width of the wavepackets is still small after the acceleration.
- Findingnone given§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
Electrons that received a momentum kick ∆p~ = -2ħ k~_L in their rest frame possess momentum p+γ∆p~ in the lab frame.
“Electrons that have received a momentum kick ∆˜ p = -2 ℏ ˜ k L in their rest frame possess a momentum p + γ ∆˜ p in the lab frame.”
Quote in the paperNot a substantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
The final distance between the two beams in the lab frame is z_A − z_B = ∆z(1−γ^−1).
“The final distance between the two beams in the lab frame is then given by z A -z B = ∆ z (1 -γ -1 ).”
Quote in the paperSubstantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
For realistic accelerations, η(t) is negligible.
“For realistic accelerations η ( t ) is negligible”
Quote in the paperSubstantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
In the rest frame of the electrons, the distance between the beams is γ(z_A−z_B) = (γ−1)∆z.
“Lorentz contraction implies that in the rest frame of the electrons the distance is then given by γ ( z A -z B ) = ( γ -1)∆ z”
Quote in the paperSubstantial claim - Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
The proper time needed to cover distance ∆z is τ=∆z/∆v~.
“If ∆˜ v = 2 ℏ ˜ k L /m denotes the relative velocity of the two partial beams in their rest frame, the proper time needed to cover this distance is given by τ = ∆ z/ ∆˜ v .”
Quote in the paperSubstantial claim - Interpretationown data§ VII. DISCUSSION · p. 6
Photon emission will not pose a problem for the proposed experiment.
“We therefore expect that photon emission will not pose a problem for the proposed experiment.”
Quote in the paperSubstantial claim - Interpretationreasoning§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
For relativistic electrons, the Doppler effect may make the detuning ∆ω~ in the electron rest frame very large, posing a practical limitation.
“For relativistic electrons this poses a practical limitation: because of the Doppler effect (terms proportional to β in Eq. (20)), the detuning ∆˜ ω in the electron rest frame may be very large.”
Quote in the paperSubstantial claim - Interpretationreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
The acceleration rule (iii) can also be used to describe the accelerated evolution of relativistic electron wavepackets.
“Consequently, Eq. (2) can also be used to describe the accelerated evolution of relativistic electron wavepackets.”
Quote in the paperSubstantial claim - Interpretationnone given§ VIII. CONCLUSION · p. 7
The key element of the proposal is the use of laser pulses to modify the electron motion via the Kapitza-Dirac effect.
“The key element of our proposal is the use of laser pulses to modify the electron motion via the KapitzaDirac effect.”
Quote in the paperSubstantial claim - Interpretationcitation§ VII. DISCUSSION · p. 6
The longitudinal pulse profile must be shaped so that the electron-pulse interaction is not switched on adiabatically.
“However, the longitudinal profile must be shaped in such a way that the electron-pulse interaction is not switched on adiabatically [38].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [38] M. Fedorov, Opt. Commun. 12 , 205 (1974), ISSN 00304018, URL http://www.sciencedirect.com/science/ article/pii/0030401874903927 .
Not checked in the free run.
- Premisecitation§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
The Kapitza-Dirac effect requires phase locking, i.e., a stable relation between the phases of the two counter-propagating laser fields.
“However, the KapitzaDirac effect requires phase locking, i.e., there must be a stable relation between the phases of the two counterpropagating laser fields [12].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [12] D. L. Freimund, K. Aflatooni, and H. Batelaan, Nature 413 , 142 (2001).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Interpretationreasoning§ VII. DISCUSSION · p. 7
In the setup shown in Fig. 1, velocity-selection would only apply to partial beam A, because beam B does not interact with the laser pulses.
“In the setup shown in Fig. 1, velocity-selection would only apply to partial beam A, because beam B does not interact with the laser pulses.”
Quote in the paperNot a substantial claim - Interpretationreasoning§ VIII. CONCLUSION · p. 7
The paper proposes an experiment in which Lorentz contraction changes the interference pattern in an electron interferometer.
“We have proposed an experiment in which Lorentz contraction changes the interference pattern in an electron interferometer.”
Quote in the paperSubstantial claim - Interpretationreasoning§ VI. BELL'S SPACESHIP PARADOX · p. 5
The mismatch in the interference experiment replaces the breaking of the string as a physical signature for the resolution of Bell's paradox.
“One may say that the mismatch in the interference experiment replaces the breaking of the string as a physical signature for the resolution of the paradox.”
Quote in the paperSubstantial claim - Interpretationreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
To realize the proposal, the time between the last two pulses must be chosen as T~ = γ ∆z m/(2ħ k~_L).
“In the lab frame, the time between the two pulses must therefore be chosen as ˜ T = γτ = γ ∆ z m/ (2 ℏ ˜ k L ).”
Quote in the paperSubstantial claim - Study design and conductreasoning§ V. NUMERICAL RESULTS · p. 4
The numerical procedure used to implement rule (iv) is more accurate than Eq. (5).
“We remark that this procedure is more accurate than Eq. (5), which neglects the actual time evolution during the laser pulses and only describes how the electron momentum is changed.”
Quote in the paperNot a substantial claim - Premisecitation§ VII. DISCUSSION · p. 6
In matter-wave interferometry, even the emission of a single photon may lead to a loss of coherence.
“In matter-wave interferometry, even the emission of a single photon may lead to a loss of coherence [39].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [39] T. Pfau, S. Sp¨ alter, C. Kurtsiefer, C. R. Ekstrom, , and J. Mlynek, Phys. Rev. Lett. 73 , 1223 (1994), URL http: //link.aps.org/abstract/PRL/v73/p1223 .
Not checked in the free run.
- Interpretationnone given§ VIII. CONCLUSION · p. 7
Using fields instead of gratings as beam splitters enables fixing the time and location of the splitting process in the rest frame of the electrons rather than in the lab frame.
“Using fields instead of gratings as beam splitters enables us to fix time and location of the splitting process in the rest frame of the electrons, rather than in the lab frame.”
Quote in the paperNot a substantial claim - Interpretationnone given§ II. SKETCH OF PROPOSED EXPERIMENT · p. 2
In the laboratory frame, the distance between beam A and B remains unchanged during the acceleration.
“in the laboratory frame, the distance between beam A and B remains unchanged during the acceleration.”
Quote in the paperSubstantial claim - Study design and conductnone given§ V. NUMERICAL RESULTS · p. 5
The non-relativistic method used provides an accurate description of the electron dynamics during the first two laser pulses.
“The method presented in the preceding paragraph is non-relativistic and provides an accurate description of the electron dynamics during the first two laser pulses.”
Quote in the paperNot a substantial claim - Premisecitation§ VII. DISCUSSION · p. 6
The magnitude of the momentum change due to a pulse envelope E is much smaller than the momentum transfer in a resonant absorption or emission process as long as the envelope changes slowly over the range of one wavelength λ, so that λ|∇E| ≪ |E|.
“As a rule of thumb, the magnitude of the momentum change due to the envelope E of a pulse is much smaller than the momentum transfer in a resonant absorption or emission process as long as the envelope changes slowly over the range of one wavelength λ , so that λ |∇E| ≪ |E| [37].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [37] H. Wallis, Physics Reports 255 , 203 (1995), ISSN 03701573, URL http://www.sciencedirect.com/science/ article/pii/037015739400090P .
Not checked in the free run.
- Interpretationreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 2
The free evolution rule (ii) can also be used for relativistic electrons.
“Using this expression for E ( p ), the free evolution rule (ii) can also be used for relativistic electrons.”
Quote in the paperSubstantial claim - Interpretationreasoning§ II. SKETCH OF PROPOSED EXPERIMENT · p. 2
After recombination, beam A and B would miss each other by a distance (γ−1)∆z.
“Consequently, after the recombination beam A and B would miss each other by a distance ∆ z ′ -∆ z = ( γ -1)∆ z”
Quote in the paperSubstantial claim - Interpretationreasoning§ VII. DISCUSSION · p. 6
The only spatial field fluctuations that would be of concern are those which couple transverse and longitudinal motion of the electrons.
“The only spatial field fluctuations that would be of concern are those which couple transverse and longitudinal motion of the electrons.”
Quote in the paperSubstantial claim - Interpretationreasoning§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4
If electrons are accelerated to the specific velocity β=(n−1)/(n+1), rule (iv) can still be used to describe the beam splitters.
“Hence, if the electrons are accelerated to a specific velocity, rule (iv) can still be used to describe the beam splitters.”
Quote in the paperSubstantial claim - Interpretationreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3
With appropriate replacements, rules (i)-(iv) and final state (6) are still valid for relativistic electrons.
“Hence, with the appropriate replacements, rules (i)-(iv) and hence final state (6) are still valid for relativistic electrons.”
Quote in the paperSubstantial claim- The authors state this as an assumption: The beam intensity is low enough that space-charge effects can be neglected.
- Interpretationreasoning§ VII. DISCUSSION · p. 6
The transverse pulse profile will not have a significant influence on the displacement between beams A and B.
“Because of point (ii) above, the transverse pulse profile will not have a significant influence on the displacement between beam A and B.”
Quote in the paperSubstantial claim - Interpretationreasoning§ Interferometry with relativistic electrons · p. 1
In the proposed experiment, Lorentz contraction of the distance between two partial beams will lead to a reduction of fringe visibility.
“We show that Lorentz contraction of the distance between two partial beams will then lead to a reduction of fringe visibility.”
- Also stated in: § I. INTRODUCTION · p. 1 · plain
“The principle idea of the proposal is that an electron beam is split, accelerated to relativistic speed and then recombined. Lorentz contraction of the distance between two partial beams will then lead to a reduction of fringe visibility.”
- Also stated in: § II. SKETCH OF PROPOSED EXPERIMENT · p. 2 · hedged
“Consequently, after the recombination beam A and B would miss each other by a distance ∆ z ′ -∆ z = ( γ -1)∆ z , which would lead to reduced fringe visibility.”
Quote in the paperSubstantial claim - Also stated in: § I. INTRODUCTION · p. 1 · plain
- Interpretationreasoning§ VIII. CONCLUSION · p. 7
The experiment is closely related to Bell's spaceship paradox, with the mismatch of the beams replacing the breaking of a string as physical evidence for Lorentz contraction.
“The experiment is closely related to Bell's spaceship paradox, with the mismatch of the beams replacing the breaking of a string as physical evidence for Lorentz contraction.”
Quote in the paperNot a substantial claim
- May combine two claims. 19
- Classified as probably not a substantial claim. 7
- The quote only partly states this claim. 1
May combine two claims.
Premisecitation§ IV. KAPITZA-DIRAC BEAM SPLITTER FOR RELATIVISTIC ELECTRONS · p. 4For non-relativistic velocities, the Dirac equation can be solved using a Foldy-Wouthuysen transformation, and the analysis of Ref. [13] can therefore be applied to the first two laser pulses.
“For non-relativistic velocities the Dirac equation can be solved using a Foldy-Wouthuysen transformation [15]. The large components of the Dirac spinor are then of the form ψ = exp( -imc 2 t/ ℏ ) ˜ ψ , where ˜ ψ is a solution to the Schr¨ odinger equation with the same vector potential. The analysis of Ref. [13] can therefore be applied to the first two laser pulses.”
Quote in the paperSubstantial claim1 of 2 sources checked- cites [15] J. D. Bjorken and S. D. Drell, Relativistic quantum mechanics (McGraw-Hill, 1998).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- cites [13] K.-P. Marzlin, Phys. Rev. A 88 , 043621 (2013), URL http://arxiv.org/abs/1307.4020 . source
May combine two claims.
Findingreasoning§ V. NUMERICAL RESULTS · p. 5The distance between wavepackets A and B in Fig. 2 is not exactly equal to the shift (γ-1)∆z derived in Sec. II, but is given by Eq. (25), because Eq. (25) accounts for the finite laser pulse duration t_L while the discussion in Secs. II and III assumes instantaneous momentum change.
“We remark that the distance between wavepackets A and B in Fig. 2 is not exactly equal to the shift ( γ -1)∆ z derived in Sec. II, but is rather given by”
- Also stated in: § V. NUMERICAL RESULTS · p. 5 · plain
“The reason is that Eq. (25) takes into account the finite duration t L of the laser pulses, while the discussion in Secs. II and III assumes that the momentum of the electrons changes instantaneously.”
Quote in the paperNot a substantial claim- The authors state this as an assumption: The momentum of the electrons changes instantaneously (as assumed in Secs. II and III).
- Also stated in: § V. NUMERICAL RESULTS · p. 5 · plain
May combine two claims.
Findingown data§ VII. DISCUSSION · p. 6For the parameters used in Sec. V, the total photon emission probability P_em(u) varies very slowly with u and is less than 5% for u > 10^-4.
“For the parameters used in Sec. V, P em ( u ) varies very slowly with u and is less than 5% for u > 10 -4 .”
Quote in the paperSubstantial claimMay combine two claims.
Findingreasoning§ III. THEORETICAL ANALYSIS OF THE INTERFEROMETER · p. 3For constant η and E(p), the maximal transition probability between positive- and negative-energy solutions is ħ2η2/(E(p)2+ħ2η2), significant only for accelerations a≈10^30 m/s2 or larger.
“For constant values of η and E ( p ) we find that the maximal transition probability is given by ℏ 2 η 2 / ( E ( p ) 2 + ℏ 2 η 2 ), which is only significant for extreme accelerations of a ≈ 10 30 m/s 2 or larger.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6The loss of coherence from photon emission is not a fundamental problem for the proposed experiment, but the associated change in electron momentum may nevertheless affect the displacement between partial beams A and B.
“While point (i) implies that this loss of coherence is not a fundamental problem, the associated change in the electron momentum may nevertheless affect the displacement between partial beams A and B.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductnone given§ VII. DISCUSSION · p. 6The theoretical analysis is based on simplifying assumptions including a homogeneous electric field, laser pulses switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x- and y-direction.
“The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
Quote in the paperSubstantial claim- The authors state this as an assumption: The electric field is homogeneous.
- The authors state this as an assumption: The laser pulses are switched on and off at specific times.
- The authors state this as an assumption: The analysis is one-dimensional and ignores forces in the x- and y-direction.
May combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 7A disadvantage of velocity-selection is that runs in which an electron has the wrong velocity will not contribute to the measurement, so the total number of experimental runs needed will be increased.
“A disadvantage of velocity-selection is that runs in which an electron has the wrong velocity will not contribute to the measurement. The total number of experimental runs needed will therefore be increased.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationreasoning§ II. SKETCH OF PROPOSED EXPERIMENT · p. 2Once electrons move at speed v, the proper distance ∆z′ in their rest frame is γ∆z, where γ=1/√(1−β2), because ∆z is the Lorentz contraction of ∆z′.
“We then have ∆ z ′ = γ ∆ z > ∆ z , where γ = 1 / √ 1 -β 2 , because ∆ z is the Lorentz contraction of ∆ z ′ .”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S4 (based).
Interpretationnone given§ VII. DISCUSSION · p. 7Temporal fluctuations in the electric field could significantly change the electron dynamics between different runs and thus make it impossible to measure the beam displacement.
“Temporal fluctuations in the electric field could significantly change the dynamics of the electrons between different runs and thus make it impossible to measure the beam displacement.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6If the two partial beams are partially overlapping, the fringe visibility can provide information about the displacement; coherence is therefore helpful but not essential.
“However, if the two partial beams are partially overlapping, the fringe visibility can provide information about the displacement. Coherence is therefore helpful but not essential.”
Quote in the paperNot a substantial claimMay combine two claims. The quote only partly states this claim.
Interpretationreasoning§ VII. DISCUSSION · p. 7The resonant interaction with laser pulses selects those electrons which have obtained the proper velocity and position to contribute to the measured observable, overcoming the problem of temporal field fluctuations.
“Thus, the resonant interaction with laser pulses selects those electrons which have obtained the proper velocity and position to contribute to the measured observable.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6The measured observable is a relative displacement of two partial beams along the direction of the laser pulses; effects on motion in other directions (such as x- or y-forces) do not affect the result, and z-forces affecting both partial beams equally do not affect the displacement.
“(ii) The measured observable is a relative displacement of two partial beams along the direction of the laser pulses. Any effects that affect the motion in other directions, such as forces in the x - or y -direction, do therefore not affect the result. Similarly, forces in the z -direction that affect both partial beams in the same way will not affect the displacement.”
Quote in the paperSubstantial claimMay combine two claims.
Study design and conductnone given§ V. NUMERICAL RESULTS · p. 4For the acceleration considered, rule (iii) provides an excellent approximation and can be evaluated directly.
“For the acceleration of 1 . 8 × 10 16 m/s 2 that we considered, rule (iii) provides an excellent approximation and can also be evaluated directly.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Premisecitation§ I. INTRODUCTION · p. 1Lorentz contraction has generally only been confirmed indirectly, for instance through the compressed charge distribution in high-energy ion collisions and the wavelength of free-electron lasers.
“Lorentz contraction generally has only been confirmed indirectly, for instance through the compressed charge distribution in high-energy ion collisions [3] and the wavelength of free-electron lasers [4].”
Quote in the paperNot a substantial claim0 of 2 sources checked- cites [3]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- cites [4]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Probably not a substantial claim: may not pass S3 (load-bearing).
Premisecitation§ VI. BELL'S SPACESHIP PARADOX · p. 5Most authors who addressed whether Lorentz contraction causes stress in the string concluded that the string in Bell's paradox would break.
“Most authors came to the conclusion that the string would break.”
Quote in the paperNot a substantial claim0 of 8 sources checked- cites [25] J. S. Bell, Speakable and unspeakable in quantum mechanics (Cambridge University Press, 2004). source
- cites [26] E. Dewan and M. Beran, Am. J. Phys. 27 , 517 (1959), URL http://link.aip.org/link/?AJP/27/517/1 .
Not checked in the free run.
- cites [31] P. J. Nawrocki, Am. J. Phys. 30 , 771 (1962), URL http: //link.aip.org/link/?AJP/30/771/1 .
Not checked in the free run.
- cites [32] E. M. Dewan, Am. J. Phys. 31 , 383 (1963), URL http: //link.aip.org/link/?AJP/31/383/1 .
Not checked in the free run.
- cites [33] D. T. Cornwell, Europhys. Lett. 71 , 699 (2005), URL http://stacks.iop.org/0295-5075/71/i=5/a=699 .
Not checked in the free run.
- cites [34] J. Franklin, European Journal of Physics 31 , 291 (2010), URL http://stacks.iop.org/0143-0807/31/i= 2/a=006 .
Not checked in the free run.
- cites [35] A. Tartaglia and M. L. Ruggiero, Europ. J. Phys. 24 , 215 (2003), URL http://stacks.iop.org/0143-0807/24/i= 2/a=361 .
Not checked in the free run.
- cites [36] D. F. Styer, Am. J. Phys. 75 , 805 (2007), URL http: //link.aip.org/link/?AJP/75/805/1 .
Not checked in the free run.
May combine two claims.
Interpretationreasoning§ VI. BELL'S SPACESHIP PARADOX · p. 5In both Bell's paradox and the proposed experiment, it is Lorentz contraction of the final separation ∆z′ that is responsible for a physical effect: the mismatch between the final positions of beams A and B in the interferometer, and the breaking of the string in Bell's paradox.
“In both cases, it is Lorentz contraction of the final separation ∆ z ′ that is responsible for a physical effect: the mismatch between the final positions of beam A and B in the electron interferometer, and the breaking of the string in Bell's paradox.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6Spatial homogeneity of the electric field is not a critical assumption, because it only matters that both partial beams achieve the same Lorentz factor γ at the end of the acceleration phase.
“Spatial homogeneity is not a critical assumption because it only matters that both partial beams achieve the same Lorentz factor γ at the end of the acceleration phase.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6Because both partial beams essentially follow the same path and are separated only along the z-axis, they undergo the same (non-constant) acceleration before recombination; hence field fluctuations along the z-axis would not affect the experimental outcome.
“Because both partial beams essentially follow the same path and are only separated along the z -axis, both beams would undergo the same (non-constant) acceleration before they are recombined. Hence, field fluctuations along the z -axis would not affect the experimental outcome.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationreasoning§ VII. DISCUSSION · p. 6In the proposed setup, pulse timing is not a problem because only partial beam A actually interacts with the pulses, while partial beam B does not obtain a momentum transfer.
“In the proposed setup this is not a problem because only partial beam A actually interacts with the pulses, while partial beam B does not obtain a momentum transfer.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductown data§ V. NUMERICAL RESULTS · p. 5The numerical results were checked by verifying that the wavefunction is normalized and that the mean position of all partial beams agrees with the position (in the rest frame of beam B) of a classical relativistic point particle receiving a specific momentum kick at each laser pulse.
“To check the numerical results we have verified that the wavefunction is normalized and the mean position of all partial beams agrees with the position (in the rest frame of beam B) of a classical relativistic point particle that receives a specific momentum kick at each laser pulse.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown data§ VI. BELL'S SPACESHIP PARADOX · p. 5Bell's spaceship paradox and the proposed interference experiment are closely related; except for the parts in which electron beams A and B are split and recombined, the two space-time diagrams coincide.
“Comparing Figs. 1b) and 3 one can see that Bell's paradox and the proposed interference experiment are closely related. Except for the parts in which electron beam A and B are split and recombined, the two space-time diagrams coincide.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone given§ V. NUMERICAL RESULTS · p. 4Rules (i) and (ii) can be evaluated exactly in momentum space.
“Rules (i) and (ii) can be evaluated exactly in momentum space.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationnone given§ VII. DISCUSSION · p. 6Strictly speaking, the proposed experiment is not an interference experiment; the measured quantity is a displacement between two partial beams, which would also be produced for incoherent electron beams.
“(i) Strictly speaking, the proposed experiment is not an interference experiment. The measured quantity is a displacement between to partial beams, which would also be produced for incoherent electron beams.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing), S4 (based).
Interpretationnone given§ VII. DISCUSSION · p. 6The beam splitting process is velocity-selective: the electron beam is only split or recombined for electrons within a specific velocity range.
“(iii) The beam splitting process is velocity-selective, i.e., the electron beam is only split or recombined for electrons within a specific velocity range.”
Quote in the paperNot a substantial claim
The authors state this as an assumption.
The beam intensity is low enough that space-charge effects can be neglected.
“It is assumed that the beam intensity is low enough so that space-charge effects can be neglected [14].”
The paper relies on this without support.
Despite the relativistic mean electron velocity, the velocity spread of the electron beam is still non-relativistic.
“To describe the last two laser pulses we can exploit that, despite the relativistic mean electron velocity, the velocity spread is still non-relativistic.”
The paper relies on this without support.
The momentum width of the wavepackets is still small after the acceleration.
“In the relativistic case we can obtain an approximate solution by exploiting that the momentum width of the wavepackets is still small after the acceleration.”
The paper relies on this without support.
For the chosen pulse duration, the laser intensities are so low that coupling to other momenta is very weak and can be neglected except when the resonance condition is fulfilled.
“However, for a pulse duration of t L = π/ (4 g 1 g 2 ) = 1 . 56 ns, where g i is defined in Eq. (7) of Ref. [13], the laser intensities are so low that this coupling is very weak and can be neglected except when resonance condition (22) (or Eq. (12) of Ref. [13] for non-relativistic electrons) is fulfilled.”
The authors state this as an assumption.
The electric field is homogeneous.
“The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
The authors state this as an assumption.
The laser pulses are switched on and off at specific times.
“The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
The authors state this as an assumption.
The analysis is one-dimensional and ignores forces in the x- and y-direction.
“The theoretical analysis that we have presented above is based on several simplifying assumptions, including a homogeneous electric field, laser pulses that are switched on and off at specific times, and a one-dimensional analysis that ignores forces in the x - and y -direction.”
The authors state this as an assumption.
The momentum of the electrons changes instantaneously (as assumed in Secs. II and III).
“The reason is that Eq. (25) takes into account the finite duration t L of the laser pulses, while the discussion in Secs. II and III assumes that the momentum of the electrons changes instantaneously.”
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Flagged first, then by citations
Research works printed but not linked: 1
- T. Matsuda, 2004, AAPPS Bull., 14, 3
Cited by
Sorted by citations
Recoil-Sensitive Lithium Interferometer without a Subrecoil Sample
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“trons [35], for example, boast GHz-recoil frequencies and would enable observation of relativistic effects [16,36].”
BackgroundMethodNonspreading relativistic electron wavepacket in a strong laser field
Campos, A. G., Hatsagortsyan, K. Z., & Keitel, C. H. (2024) · Physical Review Research · doi:10.1103/physrevresearch.6.023040 · Cited by 4 · see citing works
“The created particle momentum in the Lab-frame is determined either by the laser field intensity, or by the γ -photon energy.”
BackgroundInfluentialHot Beats and Tune Outs: Atom Interferometry with Laser-cooled Lithium
Cassella, K. (2018) · eScholarship (California Digital Library) · Cited by 1 · see citing works
- Authors
- Marzlin, K.-P., & Lee, T.
- Affiliations
- University of Calgary (CA)
- St. Francis Xavier University (CA)
- ORCID
- Marzlin, K.-P.
- Venue
- Physical Review A
- Publisher
- American Physical Society (APS)
- Published
- 2014-06-04
- Volume
- 89
- Issue
- 6
- ISSN
- 0556-2791 (ISSN-L)
- 1050-2947
- 1094-1622
- OpenAlex
- W2079823567
- Semantic Scholar
- caa56dec0166abbc3de2b0ce38fdf80f8f202231
- Cited by
- 3
- References
- 42
- Citations by year
- 2024: 1 · 2018: 1 · 2017: 1
- FWCI
- 0.17
- Type
- journal article
- Language
- en
- Open access
- green
- arxiv.org
- Locations
- Physical Review A (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- arXiv (Cornell University)
- Topics
- Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum Mechanics and Applications
- Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum and Classical Electrodynamics
- Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Atomic and Molecular Physics
- Keywords
- electron interferometry, length contraction, Kapitza-Dirac effect, relativistic electrons, fringe visibility, special relativity
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