University of Connecticut

Events Calendar

Condensed Matter Physics Seminar

Wednesday, December 1, 2021
1:00pm – 2:00pm

Storrs Campus
GW-119

Prof. Hugh Churchill, University of Arkansas

Quantum Devices with 2D Insulators and Semiconductors

I will describe two applications of 2D layered materials for quantum devices. First, I will discuss gate-tunable Josephson junction field-effect transistors (JJ-FETs) based on Al/InAs in which the gate dielectric is thin hBN. Comparing devices with hBN and AlOx dielectrics, we observe that the product of normal resistance and critical current, IcRn, is comparable for both types of devices. However, Rn is strikingly higher for the hBN-based devices indicating that the surface is doped less compared to AlOx gate dielectric. These results demonstrate that hBN provides a superior gate dielectric compared to AlOx for JJ-FET devices with applications in superconducting logic and quantum information technologies such as gatemon qubits and topological superconductivity. Second, I will discuss our work to fabricate and characterize gate-defined, accumulation mode quantum dots using monolayer and bilayer WSe2. Temperature dependence of conductance in the Coulomb-blockade regime is consistent with transport through a single level, and excited-state transport through the dots is observed at temperatures up to 10 K. These devices provide a platform to evaluate valley-spin states in monolayer and bilayer WSe2 for application as qubits. I will also briefly advertise the recently established MonArk NSF Quantum Foundry which seeks to accelerate the fabrication and characterization of 2D quantum materials to serve a broad community of users.

Contact:

Prof. I. Sochnikov

Physics Department (primary)

Control Panel