Electrostatic control of quantum phases in KTaO3-based planar constrictions

Fuente: arXiv
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Autores principales: McCourt, Jordan T., Arnault, Ethan G., Baksi, Merve, Poage, Samuel J., Salmani-Rezaie, Salva, Kumah, Divine P., Ahadi, Kaveh, Finkelstein, Gleb
Formato: Preprint
Publicado: 2025
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author McCourt, Jordan T.
Arnault, Ethan G.
Baksi, Merve
Poage, Samuel J.
Salmani-Rezaie, Salva
Kumah, Divine P.
Ahadi, Kaveh
Finkelstein, Gleb
author_facet McCourt, Jordan T.
Arnault, Ethan G.
Baksi, Merve
Poage, Samuel J.
Salmani-Rezaie, Salva
Kumah, Divine P.
Ahadi, Kaveh
Finkelstein, Gleb
contents Two-dimensional electron gases (2DEGs) formed at complex oxide interfaces offer a unique platform to engineer quantum nanostructures. However, scalable fabrication of locally addressable devices in these materials remains challenging. Here, we demonstrate an efficient fabrication approach by patterning narrow constrictions in a superconducting KTaO3-based heterostructure. The constrictions are individually tunable via the coplanar side gates formed within the same 2DEG plane. Our technique leverages the high dielectric permittivity of KTaO3 (epsilon_r ~ 5000) to achieve strong electrostatic modulation of the superconducting 2DEG. Transport measurements through the constriction reveal a range of transport regimes: Within the superconducting state, we demonstrate efficient modulation of the critical current and Berezinskii Kosterlitz Thouless (BKT) transition temperature at the weak link. Further tuning of the gate voltage reveals an unexpectedly regular Coulomb blockade pattern. All of these states are achievable with a side gate voltage |V_SG| < 1 V. The fabrication process is scalable and versatile, enabling a platform both to make superconducting field-effect transistors and to study a wide array of physical phenomena present at complex oxide interfaces.
format Preprint
id arxiv_https___arxiv_org_abs_2506_18894
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Electrostatic control of quantum phases in KTaO3-based planar constrictions
McCourt, Jordan T.
Arnault, Ethan G.
Baksi, Merve
Poage, Samuel J.
Salmani-Rezaie, Salva
Kumah, Divine P.
Ahadi, Kaveh
Finkelstein, Gleb
Superconductivity
Mesoscale and Nanoscale Physics
Two-dimensional electron gases (2DEGs) formed at complex oxide interfaces offer a unique platform to engineer quantum nanostructures. However, scalable fabrication of locally addressable devices in these materials remains challenging. Here, we demonstrate an efficient fabrication approach by patterning narrow constrictions in a superconducting KTaO3-based heterostructure. The constrictions are individually tunable via the coplanar side gates formed within the same 2DEG plane. Our technique leverages the high dielectric permittivity of KTaO3 (epsilon_r ~ 5000) to achieve strong electrostatic modulation of the superconducting 2DEG. Transport measurements through the constriction reveal a range of transport regimes: Within the superconducting state, we demonstrate efficient modulation of the critical current and Berezinskii Kosterlitz Thouless (BKT) transition temperature at the weak link. Further tuning of the gate voltage reveals an unexpectedly regular Coulomb blockade pattern. All of these states are achievable with a side gate voltage |V_SG| < 1 V. The fabrication process is scalable and versatile, enabling a platform both to make superconducting field-effect transistors and to study a wide array of physical phenomena present at complex oxide interfaces.
title Electrostatic control of quantum phases in KTaO3-based planar constrictions
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2506.18894