Events in Physics
Tuesday, February 21, 2012
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Dr. Arzhang Ardavan (University of Oxford)P523Quantum Information Processing with Artificial Molecular Nanomagnets The quantum spins associated with electrons and nuclei, with their discrete quantum levels and weak interactions with other degrees of freedom, offer a natural class of systems for embodying quantum information. Many possible condensed matter electron-spin-based qubits have been examined, including, for example, paramagnetic defects and bound donors in semiconductors, self-assembled and lithographically defined quantum dots, and various paramagnetic molecular systems. High spin systems (for which S > 1=2) with anisotropy, such as artificial molecular nanomagnets, offer the possibility of higher density information storage and may host quantum algorithms locally. We have studied the phase coherence of spin states in nanomagnets and optimised the phase memory time by chemical engineering of the molecular structures. Traditionally, quantum spin states are manipulated using static and resonant magnetic fields. However, electrically-controllable spin qubits would offer substantial architectural advantages for the design of a quantum information processor because electric elds may be applied over shorter length scales than magnetic fields. Certain kinds of molecular magnets, for example those exhibiting spin frustration and broken inversion symmetry in their internal structure, may be suitable candidates. |