arXiv subjects

Mikhail Belianchikov

Publications and source records attributed to Mikhail Belianchikov.

4 recordsLinked to original sources

arXiv2026

Sensitive detection of the Rydberg transition in trapped electrons on liquid helium using radio-frequency reflectometry

Radio-frequency reflectometry, which probes small changes in the electrical impedance of a device, provides a useful method for sensitive and fast detection of dynamic processes in quantum systems. We use this method to detect excitation of the quantized motional (Rydberg) states of trapped electrons on liquid helium. The Rydberg transition in an ensemble of electrons is detected by a change in the impedance of an rf circuit coupled to the microwave-excited electrons. To elucidate the origin of the observed response, the result is compared with an independent impedance measurement on the same electron system modulated by an electrostatic potential and with a numerical simulation using the Green's function method. Additionally, it is found that the rf response to the Rydberg resonance can be strongly enhanced by a resonant mode of the electron collective motion. Our results suggest that the observed response to the Rydberg resonance must be attributed to the lateral motion of the many-electron system rather than the vertical displacement of the individually excited electrons, as was explicate earlier. A theoretical analysis of the expected response due to the vertical displacement is given.

cond-mat.mes-hall↗

arXiv2025

Effect of helium surface fluctuations on the Rydberg transition of trapped electrons

Electrons trapped on the surface of liquid helium is an extremely clean system which holds promise for a scalable qubit platform. However, the superfluid surface is not free from fluctuations which might cause the decay and dephasing of the electrons quantized states. Understanding and mitigating these fluctuations is essential for the advancement of electrons-on-helium (eHe) qubit technology. Some work has been recently done to investigate surface oscillations due to the mechanical vibration of the cryostat using a superconducting coplanar waveguide (CPW) resonator. In the present work, we focus on a sub-hertz frequency range and observe a strong effect of surface oscillations on the temporal dynamics of the Rydberg transition of electrons confined in a microchannel trapping device. We suggest possible origin of such oscillations and find a reasonable agreement between the corresponding estimation of the oscillation frequency and the observed result.

cond-mat.mes-hall↗

arXiv2025

Image-charge detection of electrons on helium in an on-chip trapping device

Electrons trapped on the surface of superfluid helium have been thought of as a useful resource for quantum computing. Such electrons show long coherence of their surface-bound (Rydberg) states combined with their easy electrostatic manipulation. Recent proposals explored the possibility of coupling the spin state of an electron and the state of its quantized motion with a promise of a highly scalable 2D architecture for a quantum computer. However, despite recent progress in the detection of quantized lateral motion of electrons using a circuit-QED setup, the manipulation of a small number of electrons and their quantum state detection remains a challenging problem. Here, we report on the detection of the Rydberg transition of electrons on superfluid helium in an on-chip microchannel device in which electrons are moved and trapped by a set of electrostatic gates. A highly sensitive image-charge detection system allows us not only to resolve the transition spectra of such electrons, but also to perform the device characterization. The demonstrated sensitivity shows the feasibility of detecting the Rydberg transition of a single electron, which can open a new pathway for a non-destructive spin-state readout.

cond-mat.mes-hall↗

arXiv2023

Cryogenic resonant amplifier for electron-on-helium image charge readout

An electron-on-helium qubit is a promising physical platform for quantum information technologies. Among all the "blueprints" for the qubit realization, a hybrid Rydberg-spin qubit seems to be a promising one towards quantum computing using electron spins. The main technological challenge on the way to such qubits is a detection of fA range image current induced by Rydberg transition of a single electron. To address this problem we aim to use a tank LC-circuit in conjunction with a high impedance and low power dissipation cryogenic amplifier. Here, we report our progress towards realization of a resonant image current detector with a home-made cryogenic amplifier based on FHX13LG HEMT. We present a detailed characterization of the transistor at room and cryogenic temperatures, as well as details of the amplifier design and performance. At the power dissipation level of amplifier well below 100~$μ$W the measured voltage and current noise level is 0.6~nV/$\sqrt{Hz}$ and below 1.5~fA/$\sqrt{Hz}$, respectively. Based on the actual image current measurements of the Rydberg transition in a many-electron system on liquid helium, we estimate SNR=8 with the measurement bandwidth 1 Hz for the detection of a single-electron transition, providing the noise level at the output is solely determined by the noise of the amplifier.

physics.app-ph↗