Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Quasiballistic (In,Ga)As Josephson field-effect transistor with molybdenum electrodes

Olausson, Louise LU and Lind, Erik LU orcid (2026) In Physical Review Applied 25(4).
Abstract

Gate-tunable Josephson junctions with molybdenum superconducting contacts are reported. The Josephson field-effect transistors are based on an (In,Ga)As quantum well heterostructure with Mo contacts deposited on a layer of heavily doped (In,Ga)As by HCl cleaning and sputtering. We reproduced the measured data using a quasiballistic model that captures the gate dependence of the critical current and considers contributions from both Andreev states in the discrete spectrum and leaky states in the continuous spectrum. We report the observation of multiple Andreev reflections (MARs) up to the fourth order, and the measured temperature dependence of the MAR features is consistent with a model describing an effective induced superconducting... (More)

Gate-tunable Josephson junctions with molybdenum superconducting contacts are reported. The Josephson field-effect transistors are based on an (In,Ga)As quantum well heterostructure with Mo contacts deposited on a layer of heavily doped (In,Ga)As by HCl cleaning and sputtering. We reproduced the measured data using a quasiballistic model that captures the gate dependence of the critical current and considers contributions from both Andreev states in the discrete spectrum and leaky states in the continuous spectrum. We report the observation of multiple Andreev reflections (MARs) up to the fourth order, and the measured temperature dependence of the MAR features is consistent with a model describing an effective induced superconducting gap beneath the contacts, approximately 55% of the gap in the Mo. The transistors are integrated into an rf-compatible geometry with Si3N4 spacers, enabling future implementation of highly scaled, compact, quantum-limited cryogenic amplifiers.

(Less)
Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Applied
volume
25
issue
4
article number
044066
publisher
American Physical Society
external identifiers
  • scopus:105037083333
ISSN
2331-7019
DOI
10.1103/8n63-zfnr
language
English
LU publication?
yes
id
cdc1620d-2dc8-4969-a507-c8784251357f
date added to LUP
2026-06-01 14:34:22
date last changed
2026-06-01 14:34:32
@article{cdc1620d-2dc8-4969-a507-c8784251357f,
  abstract     = {{<p>Gate-tunable Josephson junctions with molybdenum superconducting contacts are reported. The Josephson field-effect transistors are based on an (In,Ga)As quantum well heterostructure with Mo contacts deposited on a layer of heavily doped (In,Ga)As by HCl cleaning and sputtering. We reproduced the measured data using a quasiballistic model that captures the gate dependence of the critical current and considers contributions from both Andreev states in the discrete spectrum and leaky states in the continuous spectrum. We report the observation of multiple Andreev reflections (MARs) up to the fourth order, and the measured temperature dependence of the MAR features is consistent with a model describing an effective induced superconducting gap beneath the contacts, approximately 55% of the gap in the Mo. The transistors are integrated into an rf-compatible geometry with Si3N4 spacers, enabling future implementation of highly scaled, compact, quantum-limited cryogenic amplifiers.</p>}},
  author       = {{Olausson, Louise and Lind, Erik}},
  issn         = {{2331-7019}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Applied}},
  title        = {{Quasiballistic (In,Ga)As Josephson field-effect transistor with molybdenum electrodes}},
  url          = {{http://dx.doi.org/10.1103/8n63-zfnr}},
  doi          = {{10.1103/8n63-zfnr}},
  volume       = {{25}},
  year         = {{2026}},
}