Microscopic scale of pair-breaking quantum phase transitions in superconducting films, nanowires and La$_{1.92}$Sr$_{0.08}$CuO$_{4}$

• URL: http://arxiv.org/abs/2309.00747v1
• Date: Fri, 1 Sep 2023 21:55:23 GMT
• Title: Microscopic scale of pair-breaking quantum phase transitions in superconducting films, nanowires and La$_{1.92}$Sr$_{0.08}$CuO$_{4}$
• Authors: Andrey Rogachev and Kevin Davenport
• Abstract summary: superconducting ground state can be created and destroyed through quantum phase transitions. Quantum phase transitions are driven by non-thermal parameters such as the carrier density or magnetic field. In this work, we find that the pair-breaking mechanism causing the suppression of the Cooper pair density gives a unifyingly consistent description of magnetic-field-driven QPTs.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The superconducting ground state in a large number of two-dimensional (2d) systems can be created and destroyed through quantum phase transitions (QPTs) driven by non-thermal parameters such as the carrier density or magnetic field. The microscopic mechanism of QPTs has not been established in any 2d superconductor, in part due to an emergent scale-invariance near the critical point, which conceals the specific processes driving the transitions. In this work, we find that the pair-breaking mechanism causing the suppression of the Cooper pair density gives a unifyingly consistent description of magnetic-field-driven QPTs in amorphous MoGe, Pb and TaN films, as well as in quasi-2d high-temperature superconductor La$_{1.92}$Sr$_{0.08}$CuO$_{4}$. This discovery was facilitated by the development of a novel theoretical approach, one which goes beyond the standard determination of critical exponents and allows for the extraction of a microscopic seeding length scale of the transitions. Remarkably, for the materials studied, and also for MoGe nanowires, this scale matches the superconducting coherence length. Further, this approach has been successfully applied to many other complex, non-superconducting systems.

Related papers

• Transport properties and quantum phase transitions in one-dimensional superconductor-ferromagnetic insulator heterostructures [44.99833362998488]
  We propose a one-dimensional electronic nanodevice inspired in recently fabricated semiconductor-superconductor-ferromagnetic insulator hybrids. We show that the device can be tuned across spin- and fermion parity-changing QPTs by adjusting the FMI layer length orange and/or by applying a global backgate voltage. Our findings suggest that these effects are experimentally accessible and offer a robust platform for studying quantum phase transitions in hybrid nanowires.
  arXiv  Detail & Related papers  (2024-10-18T22:25:50Z)
• Proximity-induced gapless superconductivity in two-dimensional Rashba semiconductor in magnetic field [0.0]
  We introduce a theoretical model describing a disordered semiconductor with strong spin-orbit coupling. Our model provides predictions for the density of states and superfluid density. Our model can be used to probe in-situ parameters of other superconductor-semiconductor heterostructures.
  arXiv  Detail & Related papers  (2023-11-15T20:10:17Z)
• Superconductivity in a Topological Lattice Model with Strong Repulsion [1.1608869880392607]
  We introduce a minimal 2D lattice model that incorporates time-reversal symmetry, band topology, and strong repulsive interactions. We demonstrate that it is formed from the weak pairing of holes atop the QSH insulator. Motivated by this, we elucidate structural similarities and differences between our model and those of TBG in its chiral limit.
  arXiv  Detail & Related papers  (2023-08-21T18:00:01Z)
• Fragmented superconductivity in the Hubbard model as solitons in Ginzburg-Landau theory [58.720142291102135]
  Superconductivity and charge density waves are observed in close vicinity in strongly correlated materials. We investigate the nature of such an intertwined state of matter stabilized in the phase diagram of the elementary $t$-$tprime$-$U$ Hubbard model. We provide conclusive evidence that the macroscopic wave functions of the superconducting fragments are well-described by soliton solutions of a Ginzburg-Landau equation.
  arXiv  Detail & Related papers  (2023-07-21T18:00:07Z)
• High-fidelity two-qubit gates of hybrid superconducting-semiconducting singlet-triplet qubits [0.0]
  Superconductors induce long-range interactions between the spin degrees of freedom of quantum dots. We show that this anisotropy is tunable and enables fast and high-fidelity two-qubit gates between singlet-triplet (ST) spin qubits. Our design is immune to leakage of the quantum information into noncomputational states.
  arXiv  Detail & Related papers  (2023-04-11T09:30:38Z)
• TOF-SIMS Analysis of Decoherence Sources in Nb Superconducting Resonators [48.7576911714538]
  Superconducting qubits have emerged as a potentially foundational platform technology. Material quality and interfacial structures continue to curb device performance. Two-level system defects in the thin film and adjacent regions introduce noise and dissipate electromagnetic energy.
  arXiv  Detail & Related papers  (2021-08-30T22:22:47Z)
• Near-Field Terahertz Nanoscopy of Coplanar Microwave Resonators [61.035185179008224]
  Superconducting quantum circuits are one of the leading quantum computing platforms. To advance superconducting quantum computing to a point of practical importance, it is critical to identify and address material imperfections that lead to decoherence. Here, we use terahertz Scanning Near-field Optical Microscopy to probe the local dielectric properties and carrier concentrations of wet-etched aluminum resonators on silicon.
  arXiv  Detail & Related papers  (2021-06-24T11:06:34Z)
• Quantum Sensors for Microscopic Tunneling Systems [58.720142291102135]
  tunneling Two-Level-Systems (TLS) are important for micro-fabricated quantum devices such as superconducting qubits. We present a method to characterize individual TLS in virtually arbitrary materials deposited as thin-films. Our approach opens avenues for quantum material spectroscopy to investigate the structure of tunneling defects.
  arXiv  Detail & Related papers  (2020-11-29T09:57:50Z)
• Experimental evidence for topological phases in the magnetoconductance of 2DEG-based hybrid junctions [0.0]
  Majorana phases emerge as quantized plateaus in the magnetoconductance of hybrid junctions based on two-dimensional electron gases (2DEG) under fully out-of-plane magnetic fields. We report on the experimental observation of such topological phases in Josephson junctions, based on In0.75Ga0.25As 2DEG, by sweeping out-of-plane magnetic fields of as small as 0 B(mT) 100.
  arXiv  Detail & Related papers  (2020-07-04T09:53:13Z)
• Waveguide Bandgap Engineering with an Array of Superconducting Qubits [101.18253437732933]
  We experimentally study a metamaterial made of eight superconducting transmon qubits with local frequency control. We observe the formation of super- and subradiant states, as well as the emergence of a polaritonic bandgap. The circuit of this work extends experiments with one and two qubits towards a full-blown quantum metamaterial.
  arXiv  Detail & Related papers  (2020-06-05T09:27:53Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.