Article
Nanoscience & Nanotechnology
Kun-Rok Jeon, Binoy Krishna Hazra, Jae-Keun Kim, Jae-Chun Jeon, Hyeon Han, Holger L. Meyerheim, Takis Kontos, Audrey Cottet, Stuart S. P. Parkin
Summary: This study reports the spin-triplet supercurrent spin valves in chiral antiferromagnetic Josephson junctions and a direct-current superconducting quantum interference device. By utilizing the Berry curvature-induced fictitious magnetic fields and the non-collinear atomic-scale spin arrangement, long-range triplet Cooper pairing is achieved in the chiral antiferromagnet Mn3Ge. The observed supercurrent spin-valve behaviors under a small magnetic field and the direct-current superconducting quantum interference device functionality are theoretically verified.
NATURE NANOTECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Aritra Lahiri, Sang -Jun Choi, Bjoern Trauzettel
Summary: Josephson tunnel junctions exhibit a supercurrent proportional to the sine of the superconducting phase difference. Voltage pulses with sharp temporal variations significantly influence the term proportional to the cosine of the phase difference. The nonequilibrium fractional Josephson effect arises from the interference of nonequilibrium virtual quasiparticle excitations, and it is independent of the ground state fermion parity in topological Josephson junctions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Ekta Bhatia, Anand Srivastava, James Devine-Stoneman, Nadia A. Stelmashenko, Zoe H. Barber, Jason W. A. Robinson, Kartik Senapati
Summary: Researchers have successfully realized a nanoscale S/F/S planar junction by patterning a ferromagnetic material, showing long-range triplet supercurrents crossing a ferromagnetic barrier. They have also demonstrated a ferromagnetic planar nano-SQUID device consisting of two spin-triplet Josephson junctions.
Article
Physics, Multidisciplinary
Si-Cong Ji, Thomas Schweigler, Mohammadamin Tajik, Federica Cataldini, Joao Sabino, Frederik S. Moller, Sebastian Erne, Jorg Schmiedmayer
Summary: In this study, Floquet engineering of tunnel coupling between a pair of one-dimensional bosonic quasicondensates in a tilted double-well potential was investigated. By modulating the energy difference between the two wells, tunnel coupling was reestablished and its amplitude and phase were precisely controlled. This allowed for coherence between two initially uncorrelated Bose gases and preparation of different initial states in the emerging sine-Gordon Hamiltonian. The Floquet system was fully characterized and the dependence of both equilibrium properties and relaxation on the modulation was studied.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
I. Bobkova, A. M. Bobkov, M. A. Silaev
Summary: Recent research focuses on ordered states that appear exclusively under time-dependent drives in quantum matter. A class of systems featuring dynamic spin-triplet superconducting order stimulated by alternating electric fields have been demonstrated. This effect is based on the interplay of ferromagnetism, interfacial spin-orbital coupling, and condensate motion driven by the field, converting hidden static p-wave order into dynamic s-wave equal-spin triplet correlations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
D. Watfa, R. Delagrange, A. Kadlecova, M. Ferrier, A. Kasumov, H. Bouchiat, R. Deblock
Summary: The high frequency emission of a carbon nanotube based Josephson junction was investigated and compared to its dc Josephson current. It was found that the Kondo effect can enhance the dc supercurrent while strongly reducing the ac Josephson effect.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Qiang Cheng, Qing Yan, Qing-Feng Sun
Summary: Our study reveals that the Josephson effect in spin-triplet superconductor-quantum anomalous Hall insulator-spin-triplet superconductor junctions strongly depends on the orientations of the d vectors in superconductors, showing different effects for different configurations.
Article
Materials Science, Multidisciplinary
I. M. Flor, A. Lacerda-Santos, G. Fleury, P. Roulleau, X. Waintal
Summary: Recent experiments have shown that electronic Mach-Zehnder interferometers of unprecedented fidelities could be built using a graphene pn junction in the quantum Hall regime. The separation between two different edge states in the junction is abnormally high and is independent of the exchange splitting value, being governed entirely by the sample geometry.
Article
Physics, Multidisciplinary
Fangzhao Alex An, Bhuvanesh Sundar, Junpeng Hou, Xi-Wang Luo, Eric J. Meier, Chuanwei Zhang, Kaden R. A. Hazzard, Bryce Gadway
Summary: The concept of synthetic dimensions has played a key role in analog simulation in atomic, molecular, and optical systems, leading to rapid advances in single-particle Hamiltonian engineering. However, strong interaction effects are conspicuously absent from most synthetic dimensions platforms. Research shows that in a lattice of coupled atomic momentum states, atomic interactions result in large and qualitative changes to dynamics in the synthetic dimension, enriching the dynamics of a one-band tight-binding model with nonlinear interactions and coherent tunneling.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Ren Zhang, Yangqian Yan, Qi Zhou
Summary: Hall ribbons and Hall cylinders, fundamental theoretical tools in condensed matter physics, have been successfully synthesized in laboratories through engineering laser-atom interactions. Converting a synthetic Hall ribbon into a synthetic Hall cylinder can naturally lead to localization, with physical observables strongly dependent on the axial magnetic flux near localization-delocalization transitions. In the irrational limit, physical observables are no longer affected by the axial flux, providing a scheme to suppress decoherence induced by fluctuations of the axial flux.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
P. Pandey, D. Beckmann, R. Danneau
Summary: This experimental study demonstrates the tuning of supercurrent in a ballistic graphene-based Josephson junction by applying a control voltage to a transverse normal channel, which changes the occupation of Andreev states in the junction and hence the magnitude of the supercurrent.
Article
Materials Science, Multidisciplinary
Chuanshuai Huang, Yajun Wei, Yongchun Tao, Jun Wang
Summary: The study shows that by controlling the orientation of the exchange field, a 0-π transition can be achieved in graphene-based superconductor-ferromagnet-R-superconductor structures, while varying the RSOC strength λ does not directly affect this transition, but it is a necessary condition for the transition induced by changing the orientation.
Article
Materials Science, Multidisciplinary
Lucila Peralta Gavensky, Gonzalo Usaj, C. A. Balseiro
Summary: We studied the transport properties of a voltage-biased Josephson junction coupled via the edges of a quantum Hall sample, finding that resonant multiple Andreev reflection processes enhance quasiparticle transmission and enable spectroscopy of one-way edge modes in these hybrid devices.
Article
Materials Science, Multidisciplinary
Xuguang Wang, Daiyu Geng, Dayu Yan, Wenqi Hu, Hexu Zhang, Shaosheng Yue, Zhenyu Sun, Shiv Kumar, Eike F. Schwier, Kenya Shimada, Peng Cheng, Lan Chen, Simin Nie, Zhijun Wang, Youguo Shi, Yi-Qi Zhang, Kehui Wu, Baojie Feng
Summary: Experimental evidence of a 2DTI in the van der Waals material Ta2Pd3Te5 has been reported, showing that each monolayer is a 2DTI with weak interlayer interactions. Measurements confirm the existence of a band gap at the Fermi level and topological edge states inside the gap, making Ta2Pd3Te5 a promising material for fabricating spintronic devices based on the QSH effect.
Article
Chemistry, Multidisciplinary
Vukan Levajac, Grzegorz P. Mazur, Nick van Loo, Francesco Borsoi, Ghada Badawy, Sasa Gazibegovic, Erik P. A. M. Bakkers, Sebastian Heedt, Leo P. Kouwenhoven, Ji-Yin Wang
Summary: This study investigates the impact of the length of InSb-Al nanowire Josephson junctions on the supercurrent resilience against magnetic fields. It is found that the critical parallel field of the supercurrent can be significantly enhanced by reducing the junction length. Particularly, in 30 nm long junctions, the supercurrent can persist up to 1.3 T parallel field, approaching the critical field of the superconducting film. Furthermore, embedding such short junctions into a superconducting loop allows for the observation of supercurrent interference at a parallel field of 1 T. These findings are highly relevant for multiple experiments on hybrid nanowires requiring a magnetic-field-resilient supercurrent.
Article
Physics, Multidisciplinary
A. Donis Vela, G. Lemut, M. J. Pacholski, C. W. J. Beenakker
Summary: The research has shown that introducing s-wave superconductivity in a topological insulator can support chirality inversion of Majorana fermions along the edge with a magnetic insulator, and this inversion can be changed by the counterflow of supercurrent. Furthermore, this chirality inversion leads to a doubling of the thermal conductance in a channel parallel to the supercurrent.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
M. J. Pacholski, G. Lemut, O. Ovdat, I Adagideli, C. W. J. Beenakker
Summary: In a Fu-Kane heterostructure, a spatially oscillating pair potential with a redundant vector can lead to a deconfinement transition of Majorana bound states, forming a dispersionless Landau level. The coherent superposition of electrons and holes in the Majorana Landau level can be detected through local density oscillations, and the striped pattern provides a way to measure the chirality of the Majorana fermions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
M. J. Pacholski, G. Lemut, J. Tworzydlo, C. W. J. Beenakker
Summary: This paper discusses the spatial discretization of the single-cone Dirac Hamiltonian on the surface of a topological insulator or superconductor, with symmetry classes A, AII, AIII, and D. By utilizing a special staggered grid, the appearance of a spurious second cone in the Brillouin zone can be avoided.
Article
Physics, Multidisciplinary
G. Lemut, M. J. Pacholski, J. Tworzydlo, C. W. J. Beenakker
Summary: We investigate the spectral statistics of a Kramers-Weyl Hamiltonian in a chaotic quantum dot. Despite having symplectic time-reversal symmetry, we observe that for small values of t, the level spacing distribution follows the orthogonal ensemble (beta = 1) instead of the expected symplectic ensemble (beta = 4). We attribute this finding to a supercell symmetry of the Hamiltonian.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Condensed Matter
A. Donis Vela, G. Lemut, M. J. Pacholski, J. Tworzydlo, C. W. J. Beenakker
Summary: In an electric field, massless Dirac fermions propagate along the field lines without backscattering, a phenomenon known as 'Klein tunneling'. However, when the Dirac equation is discretized in space and time, this effect may be lost. To address this issue, we propose a staggered space-time lattice discretization method that avoids the spurious breakdown of Klein tunneling caused by fermion doubling.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Multidisciplinary
A. Donis Vela, M. J. Pacholski, G. Lemut, G. Tworzydlo, C. W. J. Beenakker
Summary: This study introduces a method to implement Dirac fermions on a space-time lattice, which can avoid the effects of scattering between multiple Dirac cones or singularities at zone boundaries on protecting symmetries. It is found that in the discretization of a single Dirac cone, the discontinuity of the time-evolution operator at Brillouin zone boundaries results in the absence of topological protection.
ANNALEN DER PHYSIK
(2022)
Review
Physics, Multidisciplinary
C. W. J. Beenakker, A. Donis Vela, G. Lemut, M. J. Pacholski, J. Tworzydlo
Summary: This article reviews methods to discretize the Hamiltonian of a topological insulator or superconductor, while preserving the topological protection of massless excitations (Dirac fermions or Majorana fermions). The method of tangent fermions, introduced by Richard Stacey, is highlighted as uniquely suitable for this purpose. Tangent fermions propagate on a 2+1 dimensional lattice with a tangent dispersion, avoiding the fermion doubling lattice error and maintaining the fundamental symmetries of the Dirac Hamiltonian. Although the discretized Hamiltonian is nonlocal, it can be transformed into a generalized eigenproblem that is local in space and time. Applications discussed include Klein tunneling, absence of localization by disorder, anomalous quantum Hall effect, and thermal metal behavior of Majorana fermions.
ANNALEN DER PHYSIK
(2023)
Article
Physics, Multidisciplinary
C. W. J. Beenakker
Summary: A method from random-matrix theory is used to calculate the pair correlation function of a one-dimensional gas of classical particles with a power-law repulsive interaction potential. An integral formula for the covariance of single-particle operators is obtained, which generalizes known results in different limits of the interaction potential. As an application, the variance of the center of mass of the gas is calculated, showing a universal large-N limit.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
D. O. Oriekhov, T. T. Osterholt, T. Vakhtel, A. R. Akhmerov, C. W. J. Beenakker
Summary: In this study, we investigate the behavior of electron propagation in a lattice with anisotropic dispersion in the x-y plane. We demonstrate that a point source generates a breathing mode, which periodically spreads and refocuses after propagating for a certain distance. Unlike classical cyclotron radius, this is a quantum mechanical effect.
Article
Materials Science, Multidisciplinary
T. Vakhtel, D. O. Oriekhov, C. W. J. Beenakker
Summary: We have identified a mapping between 2D electron transport in a minimally twisted graphene bilayer and a 1D quantum walk, where one spatial dimension acts as time. This mapping allows us to observe Bloch oscillations in purely DC transport as magnetoconductance oscillations with periodicity set by the Bloch frequency.
Article
Materials Science, Multidisciplinary
G. Lemut, M. J. Pacholski, C. W. J. Beenakker
Summary: The study shows that the direction of the magnetic field with respect to the vector separating Weyl points of opposite chirality in a Weyl superconductor affects the electrical conduction.
Article
Materials Science, Multidisciplinary
D. O. Oriekhov, Y. Cheipesh, C. W. J. Beenakker
Summary: We investigate the staircase I-V characteristic generated by Rabi oscillations in a Josephson junction with a resonant level, providing a way to probe the coherence of the qubit. This phenomenon is similar to the Majorana-induced DC Shapiro steps in topological Josephson junctions, but now for a nontopological Andreev qubit.
Article
Physics, Multidisciplinary
Valla Fatemi, Anton R. Akhmerov, Landry Bretheau
Summary: Weyl Josephson circuits that simulate Weyl band structures have been introduced. By designing circuits analogous to desired dimensionalities and symmetry classes of Bloch Hamiltonians, a six-junction device has been constructed, capable of producing a three-dimensional Weyl Hamiltonian with broken inversion symmetry and triggering topological phase transitions. It is argued that current superconducting circuit technology allows experiments to probe topological properties inaccessible in condensed matter systems.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Physics, Multidisciplinary
Inanc Adagideli, Fabian Hassler, Aurelien Grabsch, Michal Pacholski, Carlo W. J. Beenakker
