Image-charge detection of the Rydberg transition of electrons on superfluid helium confined in a microchannel structure

TL;DR

This paper demonstrates a novel image-charge detection method for Rydberg transitions of electrons on superfluid helium within microchannels, showing potential for quantum state readout and scalability to single-electron detection.

Contribution

It introduces a microchannel-based platform enabling enhanced detection of electron Rydberg transitions, advancing toward single-electron quantum state measurement.

Findings

Detection signal significantly enhanced by proximity to electrodes.

Transition frequency controllable via dc bias voltages.

Good agreement between measured and calculated transition frequencies.

Abstract

The image-charge detection provides a new direct method for the detection of the Rydberg transition in electrons trapped on the surface of liquid helium. The interest in this method is motivated by the possibility to accomplish the spin state readout for a single trapped electron, thus opening a new pathway towards using electron spins on liquid helium for quantum computing. Here, we report on the image-charge detection of the Rydberg transition in a many-electron system confined in an array of 20-um wide and 4-um deep channels filled with superfluid helium. Such detection is made possible because of a significant enhancement of the image-charge signal due to close proximity of trapped electrons to the electrodes embedded in the microchannel structure. The transition frequency of electrons in the range of 400-500~GHz is highly controllable by the dc bias voltages applied to the device and is in a good agreement with our calculations. This work demonstrates that microchannel structures provide a suitable platform for electron manipulation and their quantum state detection, with a feasibility of scaling the detection method to a single electron.