Measuring the decoherence rate in a semiconductor charge qubit

TL;DR

This paper proposes a method to measure decoherence times in semiconductor charge qubits by using adiabatic electric field control and probability measurements, feasible with current technology.

Contribution

It introduces a novel measurement technique for decoherence in solid state qubits using adiabatic control and probability analysis.

Findings

Decoherence rates due to electromagnetic fluctuations and phonons estimated.

Method feasible with existing technology and control electronics.

Provides a practical approach for decoherence measurement in semiconductor qubits.

Abstract

We describe a method by which the decoherence time of a solid state qubit may be measured. The qubit is coded in the orbital degree of freedom of a single electron bound to a pair of donor impurities in a semiconductor host. The qubit is manipulated by adiabatically varying an external electric field. We show that, by measuring the total probability of a successful qubit rotation as a function of the control field parameters, the decoherence rate may be determined. We estimate various system parameters, including the decoherence rates due to electromagnetic fluctuations and acoustic phonons. We find that, for reasonable physical parameters, the experiment is possible with existing technology. In particular, the use of adiabatic control fields implies that the experiment can be performed with control electronics with a time resolution of tens of nanoseconds.