Time-reversal symmetry breaking in microscopic single-crystal Sr$_2$RuO$_4$ devices

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Fermin, Remko, Rog, Matthijs, Stam, Guido, Wielens, Daan, Ridderbos, Joost, Li, Chuan, Maeno, Yoshi, Aarts, Jan, Lahabi, Kaveh
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866915262312218624
author Fermin, Remko
Rog, Matthijs
Stam, Guido
Wielens, Daan
Ridderbos, Joost
Li, Chuan
Maeno, Yoshi
Aarts, Jan
Lahabi, Kaveh
author_facet Fermin, Remko
Rog, Matthijs
Stam, Guido
Wielens, Daan
Ridderbos, Joost
Li, Chuan
Maeno, Yoshi
Aarts, Jan
Lahabi, Kaveh
contents Time-reversal symmetry breaking superconductivity is a quintessential unconventional quantum state. In Josephson junctions, time-reversal symmetry breaking manifests itself in the supercurrent interference pattern as the invariance of the critical current under the reversal of both transport and magnetic field directions, i.e., $I_\text{c+}(H) = I_\text{c-}(-H)$. So far, such systems have been realized in devices where superconductivity is injected into a deliberately constructed weak link medium, usually carefully tuned by external magnetic fields and electrostatic gating. In this work, we report time-reversal symmetry breaking in spontaneously emerging Josephson junctions without intentionally constructed weak links. This is realized in ultra-pure single-crystal microstructures of Sr$_2$RuO$_4$, an unconventional superconductor with a multi-component order parameter. Here, the Josephson effect emerges intrinsically at the superconducting domain wall, where the degenerate states partially overlap. In addition to violating $I_\text{c+}(H) = I_\text{c-}(-H)$, we find a rich variety of exotic transport phenomena, including a supercurrent diode effect present in the entire interference pattern, two-channel critical current oscillations with a period that deviates from $Φ_0$, fractional Shapiro steps, and current-switchable bistable states with highly asymmetric critical currents. Our findings provide direct evidence of TRSB in unstrained Sr$_2$RuO$_4$ and reveal the potential of domain wall Josephson junctions, which can emerge in any superconductor where the pairing symmetry is described by a multi-component order parameter.
format Preprint
id arxiv_https___arxiv_org_abs_2504_19361
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Time-reversal symmetry breaking in microscopic single-crystal Sr$_2$RuO$_4$ devices
Fermin, Remko
Rog, Matthijs
Stam, Guido
Wielens, Daan
Ridderbos, Joost
Li, Chuan
Maeno, Yoshi
Aarts, Jan
Lahabi, Kaveh
Superconductivity
Strongly Correlated Electrons
Time-reversal symmetry breaking superconductivity is a quintessential unconventional quantum state. In Josephson junctions, time-reversal symmetry breaking manifests itself in the supercurrent interference pattern as the invariance of the critical current under the reversal of both transport and magnetic field directions, i.e., $I_\text{c+}(H) = I_\text{c-}(-H)$. So far, such systems have been realized in devices where superconductivity is injected into a deliberately constructed weak link medium, usually carefully tuned by external magnetic fields and electrostatic gating. In this work, we report time-reversal symmetry breaking in spontaneously emerging Josephson junctions without intentionally constructed weak links. This is realized in ultra-pure single-crystal microstructures of Sr$_2$RuO$_4$, an unconventional superconductor with a multi-component order parameter. Here, the Josephson effect emerges intrinsically at the superconducting domain wall, where the degenerate states partially overlap. In addition to violating $I_\text{c+}(H) = I_\text{c-}(-H)$, we find a rich variety of exotic transport phenomena, including a supercurrent diode effect present in the entire interference pattern, two-channel critical current oscillations with a period that deviates from $Φ_0$, fractional Shapiro steps, and current-switchable bistable states with highly asymmetric critical currents. Our findings provide direct evidence of TRSB in unstrained Sr$_2$RuO$_4$ and reveal the potential of domain wall Josephson junctions, which can emerge in any superconductor where the pairing symmetry is described by a multi-component order parameter.
title Time-reversal symmetry breaking in microscopic single-crystal Sr$_2$RuO$_4$ devices
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2504.19361