Phase and amplitude of Aharonov-Bohm oscillations in nonlinear three-terminal transport through a double quantum dot

Article

关键词: IRREVERSIBLE-PROCESSES;    RECIPROCAL RELATIONS;    INTERFERENCE;    COHERENCE;    INTERFEROMETER;    ASYMMETRY;   

DOI  :  10.1103/PhysRevB.83.235310

来源: SCIE

【 摘 要 】

We study three-terminal linear and nonlinear transport through an Aharonov-Bohm interferometer containing a double quantum dot using the nonequilibrium Green function method. Under the condition that one of the three terminals is a voltage probe, we show that the linear conductance is symmetric with respect to the magnetic field (phase symmetry). However, in the nonlinear-transport regime, the phase symmetry is broken. Unlike two-terminal transport, the phase symmetry is broken even in noninteracting electron systems. Based on the lowest-order nonlinear conductance coefficient with respect to the source-drain bias voltage, we discuss the direction in which the phase shifts with the magnetic field. When the higher harmonic components of the Aharonov-Bohm oscillations are negligible, the phaseshift is a monotonically increasing function with respect to the source-drain bias voltage. To observe the Aharonov-Bohm oscillations with higher visibility, we need strong coupling between the quantum dots and the voltage probe. However, this leads to dephasing since the voltage probe acts as a Buttiker dephasing probe. The interplay between such antithetic concepts provides a peak in the visibility of the Aharonov-Bohm oscillations when the coupling between the quantum dots and the voltage probe changes.

【 授权许可】

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