Special Condensed Matter Seminar | Prof. Guido Burkard, Konstanz U. | "Electric-dipole control and coupling of spin qubits" | PCTS Seminar Room 407

Tue, May 8, 2018, 1:30 pm
Location: 
PCTS Seminar Room, 407
Speaker(s): 

Abstract: 

Spin qubits in dilute nuclear-spin materials such as silicon and carbon are currently among the most coherent systems for quantum information processing.

Yet, while the small magnetic moment associated with electron spins provides excellent shielding of the quantum information from external noise, it also limits the controllability of spin qubits with magnetic fields.   In this talk, we address the prospects for quantum control of spin qubits using electric fields from a theory point of view. We discuss various physical mechanisms that endow electron spins with an electric dipole, such as the spin-orbit coupling, magnetic field gradients, and the exclusion principle for multi-electron qubits. In this context we report on the progress in realizing electrically driven quantum gates in silicon and the achievement of the strong coupling regime between spin qubits and a superconducting microwave resonator.  Electric controllability comes at the price of an increased sensitivity of the spin qubit;  to counteract this, we show that theoretical analysis can provide new shielding techniques against electric noise.