Quantum dot thermometry at ultra-low temperature in a dilution refrigerator with a ${}^4$He immersion cell

Abstract

Experiments performed at a temperature of a few millikelvin require effective thermalization schemes, low-pass filtering of the measurement lines and low-noise electronics. Here, we report on the modifications to a commercial dilution refrigerator with a base temperature of 3.5 mK that enable us to lower the electron temperature to 6.7 mK measured from the Coulomb peak width of a quantum dot gate-defined in an [Al]GaAs heteostructure. We present the design and implementation of a liquid ${}^4$He immersion cell tight against superleaks, implement an innovative wiring technology and develop optimized transport measurement procedures.

9 pages, 5 figures

References in corpus (7)

• Non-Abelian Anyons and Topological Quantum Computation
• Aharonov-Bohm interference of fractional quantum Hall edge modes
• Primary thermometry triad at 6 mK in mesoscopic circuits
• Measuring the degeneracy of discrete energy levels using a GaAs/AlGaAs quantum dot
• On-and-off chip cooling of a Coulomb blockade thermometer down to 2.8 mK
• Disappearance of the metal-like behavior in GaAs two-dimensional holes below 30 mK
• Temperature-stabilized differential amplifer for low-noise DC measurements

Cited by in corpus (1)

• Non-galvanic calibration and operation of a quantum dot thermometer