Karsten Flensberg
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View article: From Kardar-Parisi-Zhang Scaling to Soliton Proliferation in Josephson Junction Arrays
From Kardar-Parisi-Zhang Scaling to Soliton Proliferation in Josephson Junction Arrays Open
We propose Josephson junction arrays as realistic platforms for observing nonequilibrium scaling laws characterizing the Kardar-Parisi-Zhang (KPZ) universality class, and space-time soliton proliferation. Focusing on a two-chain ladder geo…
View article: Non-Hermitian Skin Effect and Electronic Nonlocal Transport
Non-Hermitian Skin Effect and Electronic Nonlocal Transport Open
Open quantum systems governed by non-Hermitian effective Hamiltonians exhibit unique phenomena, such as the non-Hermitian skin effect, where eigenstates localize at system boundaries. We investigate this effect in a Rashba nanowire coupled…
From Kardar-Parisi-Zhang scaling to soliton proliferation in Josephson junction arrays Open
We propose Josephson junction arrays as realistic platforms for observing nonequilibrium scaling laws characterizing the Kardar-Parisi-Zhang (KPZ) universality class, and space-time soliton proliferation. Focusing on a two-chain ladder geo…
Andreev crystals in hybrid Josephson junction arrays Open
Andreev bound states are superpositions of electrons and holes in a metal that form by coherent reflection from a superconductor. When the length of the superconductor is comparable to the superconducting coherence length, Andreev bound st…
Adiabatic nonabelian braiding of imperfect Majoranas Open
Demonstration of a nontrivial result of quasiparticle exchange (or braiding) is usually considered the definitive proof of a topological phase with nonabelian excitations, such as Majorana bound states (MBSs). However, in finite systems wi…
View article: Data Catalog for: Flux-induced topological superconductivity in full-shell nanowires
Data Catalog for: Flux-induced topological superconductivity in full-shell nanowires Open
Data Catalog for: Flux-induced topological superconductivity in full-shell nanowires
Phase-controlled minimal Kitaev chain in multiterminal Josephson junctions Open
This repository contains the dataset required to reproduce all the figures of the article "Samuel D. Escribano, Anders Enevold Dahl, Karsten Flensberg and Yuval Oreg, Phase-controlled minimal Kitaev chain in multiterminal Josephson junctio…
Signatures of exceptional points in multiterminal superconductor-normal metal junctions Open
We study a non-Hermitian, multiterminal superconducting-normal system in order to identify experimental signatures of exceptional points. We focus on a minimal setting with a single spinful level, spin-dependent normal leads, and a noncoll…
Superconducting Proximity Effect in Two-Dimensional Hole Gases Open
Technology involving hybrid superconductor-semiconductor materials is a promising avenue for engineering quantum devices for information storage, manipulation, and transmission. Proximity-induced superconducting correlations are an essenti…
View article: Phase-Biased Andreev Diffraction Grating
Phase-Biased Andreev Diffraction Grating Open
In optical diffraction, the phase difference between sources in a grating or multi-slit mask is determined by the angle to the imaging screen, yielding the familiar multi-lobed diffraction image. Here, we realize a similar phenomenon in a …
View article: Fermion-parity qubit in a proximitized double quantum dot
Fermion-parity qubit in a proximitized double quantum dot Open
Bound states in quantum dots coupled to superconductors can be in a coherent superposition of states with different electron number but with the same fermion parity. Electrostatic gating can tune this superposition to a sweet spot, where t…
Fast universal control of a flux qubit via exponentially tunable wave-function overlap Open
Fast, high-fidelity control and readout of protected superconducting qubits are fundamentally challenging due to their inherent insensitivity. We propose a flux qubit variation which enjoys a tunable level of protection against relaxation …
Majorana Qubits and Non-Abelian Physics in Quantum Dot–Based Minimal Kitaev Chains Open
The possibility of engineering artificial Kitaev chains in arrays of quantum dots coupled via narrow superconducting regions has emerged as an attractive way to overcome the disorder issues that complicate the realization and detection of …
View article: Resistivity Tensor of Vortex-Lattice States in Josephson Junction Arrays
Resistivity Tensor of Vortex-Lattice States in Josephson Junction Arrays Open
Two-dimensional Josephson junction arrays frustrated by a perpendicular magnetic field are predicted to form a cascade of distinct vortex lattice states. Here, we show that the resistivity tensor provides both structural and dynamical info…
View article: Fermion-parity qubit in a proximitized double quantum dot
Fermion-parity qubit in a proximitized double quantum dot Open
Bound states in quantum dots coupled to superconductors can be in a coherent superposition of states with different electron number but with the same fermion parity. Electrostatic gating can tune this superposition to a sweet spot, where t…
Roadmap towards Majorana qubits and nonabelian physics in quantum dot-based minimal Kitaev chains Open
The possibility to engineer artificial Kitaev chains in arrays of quantum dots coupled via narrow superconducting regions has emerged as an attractive way to overcome the disorder issues that complicate the realization and detection of top…
Resistivity tensor of vortex-lattice states in Josephson junction arrays Open
Two-dimensional Josephson junction arrays frustrated by a perpendicular magnetic field are predicted to form a cascade of distinct vortex lattice states. Here, we show that the resistivity tensor provides both structural and dynamical info…
Nonsinusoidal current-phase relations in semiconductor–superconductor– ferromagnetic insulator devices Open
Coherent tunneling processes of multiple Cooper pairs across a Josephson junction give rise to high harmonics in the current phase relation. In this work, we propose and study Josephson junctions based on semiconductor-superconductor-ferro…
Non-Abelian holonomy of Majorana zero modes coupled to a chaotic quantum dot Open
If a quantum dot is coupled to a topological superconductor via tunneling contacts, each contact hosts a Majorana zero mode in the limit of zero transmission. Close to a resonance and at a finite contact transparency, the resonant level in…
Fast universal control of a flux qubit via exponentially tunable wave-function overlap Open
Fast, high fidelity control and readout of protected superconducting qubits are fundamentally challenging due to their inherent insensitivity. We propose a flux qubit variation which enjoys a tunable level of protection against relaxation …
Orbital-free approach for large-scale electrostatic simulations of quantum nanoelectronics devices Open
The route to reliable quantum nanoelectronic devices hinges on precise control of the electrostatic environment. For this reason, accurate methods for electrostatic simulations are essential in the design process. The most widespread metho…
Nonsinusoidal current-phase relations in semiconductor-superconductor-ferromagnetic insulator devices Open
Coherent tunneling processes of multiple Cooper pairs across a Josephson junction give rise to higher harmonics in the current phase relation. In this work, we propose and study Josephson junctions based on semiconductor-superconductor-fer…
Phase Asymmetry of Andreev Spectra From Cooper-Pair Momentum Open
In analogy to conventional semiconductor diodes, the Josephson diode exhibits superconducting properties that are asymmetric in applied bias. The effect has been investigated in number of systems recently, and requires a combination of bro…
Multiterminal transport spectroscopy of subgap states in Coulomb-blockaded superconductors Open
Subgap states are responsible for the low-bias transport features of hybrid superconducting-semiconducting devices. Here we analyze the local and nonlocal differential conductance of Coulomb-blockaded multiterminal superconducting islands …
Conductance matrix symmetries of multiterminal semiconductor-superconductor devices Open
Nonlocal tunneling spectroscopy of multiterminal semiconductor-superconductor hybrid devices is a powerful tool to investigate the Andreev bound states below the parent superconducting gap. We examine how to exploit both microscopic and ge…
Detecting Majorana modes by readout of poisoning-induced parity flips Open
Reading out the parity degree of freedom of Majorana bound states is key to demonstrating their nonabelian exchange properties. Here, we present a low-energy model describing localized edge states in a two-arm device. We study parity-to-ch…
Multiterminal transport spectroscopy of subgap states in Coulomb-blockaded superconductors Open
Subgap states are responsible for the low-bias transport features of hybrid superconducting--semiconducting devices. Here, we analyze the local and nonlocal differential conductance of Coulomb-blockaded multiterminal superconducting island…
Readout of Parafermionic States by Transport Measurements Open
Recent experiments have demonstrated the possibility of inducing superconducting pairing into counterpropagating fractional quantum Hall edge modes. This paves the way for the realization of localized parafermionic modes, non-Abelian anyon…
Control of Andreev bound states using superconducting phase texture Open
Andreev bound states with opposite phase-inversion asymmetries are observed in local and non-local tunneling spectra at the two ends of a superconductor-semiconductor-superconductor planar Josephson junction in the presence of a perpendicu…