Abstract
We report on low-temperature noise measurements of a single electron transistor (SET) immersed in superfluid 4He. The device acts as a charge sensitive electrometer able to detect the fluctuations of charged defects in close proximity to the SET. In particular, we measure telegraph switching of the electric current through the device originating from a strongly coupled individual two-level fluctuator. By embedding the device in a superfluid helium immersion cell, we are able to systematically control the thermalizing environment surrounding the SET and investigate the effect of the superfluid on the SET noise performance. We find that the presence of superfluid 4He can strongly suppress the switching rate of the defect by cooling the surrounding phonon bath.
| Original language | English |
|---|---|
| Pages (from-to) | 143-154 |
| Number of pages | 12 |
| Journal | Journal of Low Temperature Physics |
| Volume | 205 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Nov 2021 |
| Externally published | Yes |
Funding
We thank M.I. Dykman, N.O. Birge, H. Byeon, L. Zhang, C. Mikolas, and B. Arnold for fruitful discussions. We also thank R. Loloee and B. Bi for technical support and use of the W.M. Keck Microfabrication Facility at MSU. This work was supported by a sponsored research grant from EeroQ Corp. J. Pollanen and D.G. Rees are co-founders and partial owners of EeroQ Corp. Additionally, J. Pollanen, J.R. Lane and J.M. Kitzman acknowledge support from the National Science Foundation via Grant Numbers DMR-170833 and DMR-2003815 as well as the valuable support of the Cowen Family Endowment at MSU. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Keywords
- Liquid helium
- Single electron transistor
- Telegraph noise
- Two-level fluctuator