Cooling of Resistive Metallic Gates on Electrons Bound to Superfluid Helium

Thermalization and temperature control of electrons in nanoscale devices helps to explore new device physics and probe interesting quantum phenomena. Recent advancements in thermometry devices have demonstrated temperature sensing for a 2-dimensional electron gas (2DEG) suspended above the surface of superfluid helium [1]. In addition, the lagging image charges in the metal electrodes beneath the 2DEG have been theorized to create a dipole with the 2DEG and dissipate energy away from the electrons, cooling the 2DEG [2]. Amorphous metal electrodes have also enabled transport of a 2DEG atop shallow sub-micron helium channels, allowing probing of cooling for shallower channel depths with large coupling between the 2DEG and their image charges [3]. Here, we investigate the ability of the lagging image charges to cool the 2DEG using a symmetric heating circuit. We report preliminary evidence of cooling at channel heights of 600 nm and lower.

[1] E. I. Kleinbaum and S. A. Lyon, Phys. Rev. Lett. 121, 236801 (2018).

[2] J. S. Shier. Am. J. Phys. 36 (3): 245–249 (1968).

[3] A. T. Asfaw et. al, J. Low Temp. Phys. 195, 300 (2019).