Rainer Blatt Abstract

Rainer Blatt Harvard - Smithsonian Institute

"A Nano-Mechanical Quantum Transducer for Spin-Spin Interactions."

ABSTRACT:

Implementaton of quantum information processing faces the contradicting requirements of combining excellent isolation to avoid decoherence with the ability to control coherent interactions in a many-body quantum system. Isolated electronic and nuclear spins in solids provide an excellent quantum memory due to their weak magnetic interactions with the environment, but for the same reason it is difficult to achieve controlled interactions of spins over distances larger than tens of nanometers. In this talk I will discuss a proposal for a novel realization of a quantum data bus for electronic spin qubits that makes us of the recent advances in cooling and manipulation of nanmechanical systems. In our approach spins are coupled to the motion of magnetized mechanical resonators via magnetic field gradients. Provided that the mechanical system is charged, the magnetic moments associated with spin qubits can be effectively amplified to enable a coherent spin-spin coupling over distances exceeding 100 micrometers via Coulimb forces. This technique os applicable for a wide class of electronic spin qubits which can be localized near the magnetized tips, it allows the design and control of multi-spin interactions using different electric circuit layouts and enables the realization of hybrid systems in which spins are coupled to solid-state charge qubits or trapped atoms and ions.