Unclear origin of local heating of two-level fluctuators from sensor-dot current

Ascertain the physical mechanism responsible for the observed local heating of two-level fluctuators by current through the sensor quantum dot in Si/SiGe quantum-dot devices.

Background

The authors observe that increasing the sensor-dot conductance or rf excitation power reduces TLF switching times, consistent with local heating of the TLFs. However, the microscopic origin of this heating is not identified.

Clarifying this mechanism is important both for accurate thermal modeling of TLFs and for assessing the reliability of charge-sensor-based proxies for qubit noise.