Advantages of Independent Heat Sinking of a Two-Stage Cryogenic Amplifier for Quantum Dot Readout

ORAL

Abstract

Reduced device electron temperature while using a cryogenic HEMT amplifier is achieved by moving the amplifier to an adjacent PCB electrically connected to the sample PCB. The amplifier PCB is directly heat sunk to the mixing chamber of a dilution refrigerator, and connects to the sample through a short stainless steel coax. Using straightforward measurements of gain and RMS noise, the two stages are tuned separately to minimize the input-referred noise for a given level of power dissipation. A single shot measurement with 650 ns rise time using 10 µW of power results in a 2.3:1 SNR and 150mK electron temperature. An electron temperature of 115 mK is achieved with lower power, and the effect of these various powers on SNR is examined for bandwidths of 540kHz and 170kHz. The large amplifier bandwidth enables high frequency lock-in measurements, resulting in lower noise data than possible without such an amplifier. The ease of use of cryogenic amplification combined with relatively low electron temperature and large bandwidth provides a useful tool for characterization of semiconductor quantum dot qubits.

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Presenters

  • Joelle Corrigan

    • Department of Physics, University of Wisconsin-Madison

Authors

  • Joelle Corrigan

    • Department of Physics, University of Wisconsin-Madison

  • Trevor Knapp

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • John Dodson

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Nathan Holman

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Brandur Thorgrimsson

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Thomas McJunkin

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Samuel Neyens

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • E. R. MacQuarrie

    • Department of Physics, University of Wisconsin-Madison

  • Ryan Foote

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Lisa Edge

    • HRL Laboratories, LLC

  • Susan Coppersmith

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Mark Alan Eriksson

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • University of Wisconsin - Madison