Abstract
We show how resonant laser spectroscopy of the trion optical transitions in a self-assembled quantum dot can be used to determine the temperature of a nearby electron reservoir. At finite magnetic field, the spin-state occupation of the Zeeman-split quantum-dot electron ground states is governed by thermalization with the electron reservoir via cotunneling. With resonant spectroscopy of the corresponding excited trion states, we map out the spin occupation as a function of magnetic field to establish optical thermometry for the electron reservoir. We demonstrate the implementation of the technique in the subkelvin temperature range where it is most sensitive and where the electron temperature is not necessarily given by the cryostat base temperature.
- Received 9 May 2014
DOI:https://doi.org/10.1103/PhysRevApplied.2.024002
© 2014 American Physical Society
Synopsis
Measuring Millikelvin Temperatures with Quantum Dots
Published 1 August 2014
Researchers have shown that millikelvin temperatures can be reliably measured using the ground-state optical properties of quantum dots.
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