---
OA_place: publisher
_id: '20371'
abstract:
- lang: eng
text: "Quantum mechanics reveals a world that defies classical determinism, where
uncertainty, superposition, and fluctuations are fundamental aspects. Engineering
devices that harness these quantum features requires not only precision, but also
a deep understanding of how they interact with their surrounding environment.
Superconducting circuits, which exploit\r\nmacroscopic quantum coherence in low-loss
superconducting materials, provide a scalable platform for implementing such systems.
Among the critical elements in these circuits, superinductors—high-impedance,
dissipation-free inductive components—play a central role by suppressing charge
fluctuations. They allow quantum states to be delocalized in phase space, protect
qubits from environmental noise, and facilitate access to phenomena such as dual
Josephson physics and ultra-strong coupling regimes. \r\nThis thesis explores
two complementary implementations of high-impedance circuits: geometric superinductors,
demonstrating that high impedance can be achieved beyond kinetic inductance,\r\nand
Josephson junction chains, used to investigate both microwave mode properties
and DC transport across the superconductor-to-insulator transition. \r\nPart I
addresses geometric superinductors. Contrary to the common belief that high-impedance
superconducting circuits require kinetic inductance, we demonstrate that purely
geometric designs can achieve characteristic impedance exceeding the resistance
quantum. By exploiting mutual coupling between adjacent turns, coil-based inductors
achieve enhanced self-inductance, creating a reliable platform for qubits and
resonators. Modeling, simulation, fabrication, and\r\ncharacterization confirm
that these elements behave as superinductor. With low loss, high linearity, and
minimal stray capacitance, these elements are reproducible, free of uncontrolled
tunneling events, and capable of strong magnetic coupling. This establishes geometric
superinductors as robust, single-wave-function superconducting devices suitable
for hardware protected qubits and hybrid systems.\r\nPart II presents classical
numerical simulations of a Quantum Phase Slip circuit to study dual Shapiro steps.
The circuit consists of an ideal Quantum Phase Slip element embedded in a resistive-inductive
environment with a parasitic capacitance.\r\nPart III extends the investigation
of high characteristic-impedance circuit elements to one-dimensional Josephson
junction chains, which act as a quantum simulator for many-body physics and the
superconductor–insulator transition. Different devices are realized on both sides
of the DC phase transition, showing either a supercurrent branch or Coulomb blockade
at zero bias. The effect of the crossover on microwave modes, however, remains
insufficiently investigated. Studying these modes provides insight into the interplay
between disorder and phase-slip events. Small differences in circuit component
sizes determine which side of the transition a device falls on, making these results
relevant not only for fundamental understanding but also for the design of quantum
devices, emphasizing the crucial role of the\r\nelectromagnetic environment in
stabilizing and controlling fragile quantum states. \r\nTogether, these results
illustrate how carefully engineered high characteristic-impedance elements provide
a link between macroscopic circuits and the inherently uncertain quantum world,
enabling experiments that probe, control, and ultimately exploit quantum fluctuations
for applications in quantum information, metrology, solid state physics and beyond.\r\n\r\n"
acknowledged_ssus:
- _id: NanoFab
- _id: M-Shop
acknowledgement: "I also gratefully acknowledge the generous support of the NOMIS
Foundation Project \"Protected\r\nStates of Quantum Matter\" and the grant from
the Beyond-C consortium. Their funding\r\nmade this research possible and gave me
the freedom to ask ambitious questions, and try to\r\nanswer them.\r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Andrea
full_name: Trioni, Andrea
id: 42F71B44-F248-11E8-B48F-1D18A9856A87
last_name: Trioni
citation:
ama: 'Trioni A. High-impedance quantum circuits for mesoscopic physics : Geometric
superinductors and insulating Josephson Chains. 2025. doi:10.15479/AT-ISTA-20371'
apa: 'Trioni, A. (2025). High-impedance quantum circuits for mesoscopic physics :
Geometric superinductors and insulating Josephson Chains. Institute of Science
and Technology Austria. https://doi.org/10.15479/AT-ISTA-20371'
chicago: 'Trioni, Andrea. “High-Impedance Quantum Circuits for Mesoscopic Physics :
Geometric Superinductors and Insulating Josephson Chains.” Institute of Science
and Technology Austria, 2025. https://doi.org/10.15479/AT-ISTA-20371.'
ieee: 'A. Trioni, “High-impedance quantum circuits for mesoscopic physics : Geometric
superinductors and insulating Josephson Chains,” Institute of Science and Technology
Austria, 2025.'
ista: 'Trioni A. 2025. High-impedance quantum circuits for mesoscopic physics :
Geometric superinductors and insulating Josephson Chains. Institute of Science
and Technology Austria.'
mla: 'Trioni, Andrea. High-Impedance Quantum Circuits for Mesoscopic Physics :
Geometric Superinductors and Insulating Josephson Chains. Institute of Science
and Technology Austria, 2025, doi:10.15479/AT-ISTA-20371.'
short: 'A. Trioni, High-Impedance Quantum Circuits for Mesoscopic Physics : Geometric
Superinductors and Insulating Josephson Chains, Institute of Science and Technology
Austria, 2025.'
corr_author: '1'
date_created: 2025-09-23T09:57:57Z
date_published: 2025-09-23T00:00:00Z
date_updated: 2026-04-15T06:43:02Z
day: '23'
ddc:
- '539'
degree_awarded: PhD
department:
- _id: GradSch
- _id: JoFi
doi: 10.15479/AT-ISTA-20371
ec_funded: 1
file:
- access_level: open_access
checksum: 6fb925648dfa5f4384814c552ee2f099
content_type: application/pdf
creator: atrioni
date_created: 2025-09-25T07:15:05Z
date_updated: 2025-09-25T14:25:31Z
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file_name: 2025_Trioni_Andrea_Thesis.pdf
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creator: atrioni
date_created: 2025-09-25T14:45:43Z
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relation: source_file
file_date_updated: 2025-09-26T07:20:48Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '202'
project:
- _id: eb9b30ac-77a9-11ec-83b8-871f581d53d2
name: Protected states of quantum matter
- _id: bdb108fd-d553-11ed-ba76-83dc74a9864f
grant_number: F07105
name: QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration
of Superconducting Quantum Circuits
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
publication_identifier:
isbn:
- 978-3-99078-067-1
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '8755'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Johannes M
full_name: Fink, Johannes M
id: 4B591CBA-F248-11E8-B48F-1D18A9856A87
last_name: Fink
orcid: 0000-0001-8112-028X
title: 'High-impedance quantum circuits for mesoscopic physics : Geometric superinductors
and insulating Josephson Chains'
type: dissertation
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2025'
...