---
OA_place: publisher
_id: '17881'
abstract:
- lang: eng
text: "This work can be broadly classified into the study of critical phenomena
in a one dimensional\r\narray of Josephson junctions. While we study quantum criticality
when the array is in thermal\r\nequilibrium at zero bias, the non-equilibrium
study involves understanding the bistability of the\r\narray at a critical non-zero
bias. This work furthers our knowledge in understanding quantum\r\ncritical behaviour
at finite temperatures in a one dimensional Josephson array, while also\r\nestablishing
relaxation behaviour dual to that observed in a single Josephson junction.\r\nChapter
1 briefly introduces the model to understand superconductor-insulator phase transition\r\nin
a one dimensional Josephson array and points out the state of the field from where
we\r\nstarted our zero-bias experiments. In this context it discusses the phase-charge
duality observed\r\nin a Josephson array and its dual hysteretic behaviour to
that of a single junction, setting the\r\nground for our non-equilibrium study
of the array.\r\nChapter 2 shows the experimental setup and the chip layout of
the device we measured.\r\nIn chapter 3 we show that, unlike the typical quantum-critical
broadening scenario, in one dimensional Josephson arrays temperature dramatically
shifts the critical region. This shift leads\r\nto a regime of superconductivity
at high temperature, arising from the melted zero-temperature\r\ninsulator. Our
results quantitatively explain the low-temperature onset of superconductivity
in\r\nnominally insulating regimes, and the transition to the strongly insulating
phase. We further\r\npresent, to our knowledge, the first understanding of the
onset of anomalous-metallic resistance\r\nsaturation [30]. This work demonstrates
a non-trivial interplay between thermal effects and\r\nquantum criticality. A
practical consequence is that, counterintuitively, the coherence of\r\nhigh-impedance
quantum circuits is expected to be stabilized by thermal fluctuations.\r\nIn chapter
4, we show relaxation oscillations in a current-biased one dimensional array of\r\nJosephson
junctions. These oscillations are well described by a circuit model, dual to the\r\nordinary
Josephson relaxation oscillations [72]. Injection locking these oscillations results
in\r\ncurrent plateaux. The relaxation step is found to obey a characteristic
self-consistent relation,\r\nsuggesting that it is governed by overheating effects.\r\nChapter
5 describes the various checks and analysis we performed to support our conclusions\r\nmade
in chapters 3 and 4.\r\nFinally, chapter 6 describes the nanofabrication steps
and the finite element electromagnetic\r\nsimulations we performed to fabricate
our devices."
acknowledged_ssus:
- _id: NanoFab
- _id: M-Shop
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Soham
full_name: Mukhopadhyay, Soham
id: FDE60288-A89D-11E9-947F-1AF6E5697425
last_name: Mukhopadhyay
orcid: 0000-0001-5263-5559
citation:
ama: Mukhopadhyay S. Thermal effects in one dimensional Josephson chains. 2024.
doi:10.15479/at:ista:17881
apa: Mukhopadhyay, S. (2024). Thermal effects in one dimensional Josephson chains.
Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:17881
chicago: Mukhopadhyay, Soham. “Thermal Effects in One Dimensional Josephson Chains.”
Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:17881.
ieee: S. Mukhopadhyay, “Thermal effects in one dimensional Josephson chains,” Institute
of Science and Technology Austria, 2024.
ista: Mukhopadhyay S. 2024. Thermal effects in one dimensional Josephson chains.
Institute of Science and Technology Austria.
mla: Mukhopadhyay, Soham. Thermal Effects in One Dimensional Josephson Chains.
Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:17881.
short: S. Mukhopadhyay, Thermal Effects in One Dimensional Josephson Chains, Institute
of Science and Technology Austria, 2024.
corr_author: '1'
date_created: 2024-09-08T10:23:25Z
date_published: 2024-09-10T00:00:00Z
date_updated: 2026-04-07T13:04:06Z
day: '10'
ddc:
- '539'
degree_awarded: PhD
department:
- _id: GradSch
- _id: AnHi
doi: 10.15479/at:ista:17881
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creator: smukhopa
date_created: 2024-09-12T10:46:04Z
date_updated: 2025-03-13T23:30:04Z
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language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '82'
project:
- _id: 0aa3608a-070f-11eb-9043-e9cd8a2bd931
grant_number: P33692
name: Cavity electromechanics across a quantum phase transition
publication_identifier:
isbn:
- 978-3-99078-043-5
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '14032'
relation: part_of_dissertation
status: public
- id: '18057'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Andrew P
full_name: Higginbotham, Andrew P
id: 4AD6785A-F248-11E8-B48F-1D18A9856A87
last_name: Higginbotham
orcid: 0000-0003-2607-2363
title: Thermal effects in one dimensional Josephson chains
type: dissertation
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2024'
...