Molecular Nanomagnets

Abstract

Molecular nanomagnets (or single‐molecule magnets (SMMs)) have attracted much interest in recent years both from experimental and theoretical points of view. These systems are organometallic clusters characterized by a large‐spin ground state with a predominant uniaxial anisotropy. The quantum nature of these systems makes them very appealing for phenomena occurring on the mesoscopic scale, that is, at the boundary between classical and quantum physics. Below their blocking temperature, they exhibit magnetization hysteresis, the classical macroscale property of a magnet, as well as quantum tunneling of magnetization (QTM) and quantum phase interference, the properties of a microscale entity. QTM is advantageous for some potential applications of SMMs, for example, in providing the quantum superposition of states for quantum computing, but it is a disadvantage in others such as information storage. It is widely accepted that SMMs have a potential for quantum computation, in particular, because they are extremely small and almost identical, allowing to obtain, in a single measurement, statistical averages of a larger number of qubits. This chapter introduces a few basic concepts that are needed to understand the quantum phenomena observed in molecular nanomagnets and it concludes by mentioning new trends of the field of molecular nanomagnets toward molecular spintronics.