arXiv subjects

Suraj Thapa Magar

Publications and source records attributed to Suraj Thapa Magar.

3 recordsLinked to original sources

arXiv2026

Visualization of Gaussian Mode Profile in Gigahertz Surface-Acoustic-Wave Resonators

Surface-acoustic-wave (SAW) resonators operating at gigahertz (GHz) frequencies are widely used in wireless telecommunication and quantum information processing. Successful implementation of such resonators calls for detailed microscopic understanding of their mode profiles, energy dissipation channels, and imperfections from microfabrication. In this work, we report on the visualization of acoustic waves in LiNbO3 SAW resonators by transmission-mode microwave impedance microscopy (TMIM). The Gaussian mode profile tightly confined by reflecting mirrors is vividly seen in the TMIM images, from which the linewidth of the resonator itself can be extracted. The spatially resolved acoustic profile also allows us to perform failure analysis on faulty devices. Our work establishes a pathway for further optimization of SAW resonators for classical and quantum acoustic applications.

physics.optics↗

arXiv2025

Pyroelectric effects in hybrid semiconductor-lithium niobate quantum devices

Hybrid quantum devices using surface acoustic waves show promise as key elements of quantum information processors. We report measurements of integrated flip-chip devices consisting of semiconductor quantum dots and surface acoustic wave resonators in lithium niobate. We observed that the pyroelectric effect in lithium niobate inhibited the operation of quantum dots in the integrated devices. GaAs/AlGaAs devices suffered from unintentional carrier depletion, and Si/SiGe devices suffered from electrostatic discharge. Our results highlight the importance of mitigating pyroelectric effects in semiconductor-lithium niobate hybrid devices for continued progress in quantum interconnects and transducers.

cond-mat.mes-hall↗

arXiv2024

High-impedance surface acoustic wave resonators

Because of their small size, low loss, and compatibility with magnetic fields and elevated temperatures, surface acoustic wave resonators hold significant potential as future quantum interconnects. Here, we design, fabricate, and characterize GHz-frequency surface acoustic wave resonators with the potential for strong capacitive coupling to nanoscale solid-state quantum systems, including semiconductor quantum dots. Strong capacitive coupling to such systems requires a large characteristic impedance, and the resonators we fabricate have impedance values above 100 $Ω$. We achieve such high impedance values by tightly confining a Gaussian acoustic mode. At the same time, the resonators also have low loss, with quality factors of several thousand at millikelvin temperatures. These high-impedance resonators are expected to exhibit large vacuum electric-field fluctuations and have the potential for strong coupling to a variety of solid-state quantum systems.

cond-mat.mes-hall↗