223 citations · 800 across the 33 of their papers we have counts for
24 papers · 1 filter
Flux noise without flux tunability in superconducting qubits
Daniel Kruti, Roman-Pascal Riwar
Flux noise is unanimously recognised as a leading dephasing mechanism for flux-tunable superconducting qubits. However, our microscopic understanding remains incomplete, and basic…
Consistent quantum treatments of non-convex kinetic energies
C. Koliofoti, M. A. Javed, R. -P. Riwar
The task of finding a consistent relationship between a quantum Hamiltonian and a classical Lagrangian is of utmost importance for basic, but ubiquitous techniques like canonical q…
Interplay between evanescent scattering modes and finite dispersion in superconducting junctions
Daniel Kruti, Roman-Pascal Riwar
Superconducting junctions are essential building blocks for quantum hardware, and their fundamental behaviour remains a highly active research field. The behaviour of generic junct…
On-demand analog space-time in superconducting networks: grey holes, dynamical instability and exceptional points
Mohammad Atif Javed, Daniel Kruti, Ahmed Kenawy +4
There has been considerable effort to mimic analog black holes and wormholes in solid state systems. Lattice realizations in particular present specific challenges. One of those is…
Limitations of Caldeira-Leggett model for description of phase transitions in superconducting circuits
O. Kashuba, R. -P. Riwar
The inherent complexity of system-bath interactions often requires making critical approximations, which we here show to have a radical influence on the renormalization group flow…
Emulating moiré materials with quasiperiodic circuit quantum electrodynamics
Tobias Herrig, Christina Koliofoti, Jedediah H. Pixley +2
Topological bandstructures interfering with moiré superstructures give rise to a plethora of emergent phenomena, which are pivotal for correlated insulating and superconducting sta…
Quasiperiodic circuit quantum electrodynamics
Tobias Herrig, Jedediah H. Pixley, Elio J. König +1
Superconducting circuits are an extremely versatile platform to realize quantum information hardware and to emulate topological materials. We here show how a simple arrangement of…
Fractional Josephson effect versus fractional charge in superconducting-normal metal hybrid circuits
Mohammad Atif Javed, Jakob Schwibbert, Roman-Pascal Riwar
Fractionally charged excitations play a central role in condensed matter physics, and can be probed in different ways. If transport occurs via dissipation-less supercurrents, they…
Compact description of quantum phase slip junctions
Christina Koliofoti, Roman-Pascal Riwar
Quantum circuit theory is a powerful and ever-evolving tool to predict the dynamics of superconducting circuits. In its language, quantum phase slips (QPSs) are famously considered…
Electromotive force in driven topological quantum circuits
Ahmed Kenawy, Fabian Hassler, Roman-Pascal Riwar
Time-dependent control of superconducting quantum circuits is a prerequisite for building scalable quantum hardware. The quantum description of these circuits is complicated due to…
Circuit quantization with time-dependent magnetic fields for realistic geometries
Roman-Pascal Riwar, David P. DiVincenzo
Quantum circuit theory has become a powerful and indispensable tool to predict the dynamics of superconducting circuits. Surprisingly however, the question of how to properly accou…
Charge quantization and detector resolution
Roman-Pascal Riwar
Charge quantization, or the absence thereof, is a central theme in quantum circuit theory, with dramatic consequences for the predicted circuit dynamics. Very recently, the questio…
Cooper-pair transistor as a minimal topological quantum circuit
Tobias Herrig, Roman-Pascal Riwar
The outlook of protected quantum computing spurred enormous progress in the search for topological materials, sustaining a continued race to find the most experimentally feasible p…
Transport fluctuation relations in interacting quantum pumps
Roman-Pascal Riwar, Janine Splettstoesser
The understanding of out-of-equilibrium fluctuation relations in small open quantum systems has been a focal point of research in recent years. In particular, for systems with adia…
Fractional charges in conventional sequential electron tunneling
Roman-Pascal Riwar
The notion of fractional charges was up until now reserved for quasiparticle excitations emerging in strongly correlated quantum systems, such as Laughlin states in the fractional…
Dissipation by normal-metal traps in transmon qubits
Roman-Pascal Riwar, Leonid I. Glazman, Gianluigi Catelani
Quasiparticles are an intrinsic source of relaxation and decoherence for superconducting qubits. Recent works have shown that normal-metal traps may be used to evacuate quasipartic…
Topological transconductance quantization in a four-terminal Josephson junction
Erik Eriksson, Roman-Pascal Riwar, Manuel Houzet +2
Recently we predicted that the Andreev bound state spectrum of 4-terminal Josephson junctions may possess topologically protected zero-energy Weyl singularities, which manifest the…
Readout of relaxation rates by nonadiabatic pumping spectroscopy
Roman-Pascal Riwar, Benoît Roche, Xavier Jehl +1
We put forward nonadiabatic charge pumping as a method for accessing the different charge relaxation rates as well as the relaxation rates of excited orbital states in double-quant…
Cross-correlations of coherent multiple Andreev reflections
Roman-Pascal Riwar, Driss M. Badiane, Manuel Houzet +2
We use the Landauer-Büttiker scattering theory for electronic transport to calculate the current cross-correlations in a voltage-biased three-terminal junction with all superconduc…
Multi-terminal Josephson junctions as topological materials
Roman-Pascal Riwar, Manuel Houzet, Julia S. Meyer +1
Topological materials and their unusual transport properties are now at the focus of modern experimental and theoretical research. Their topological properties arise from the bands…
A two-atom electron pump
B. Roche, R. -P. Riwar, B. Voisin +6
The fabrication of single atom transistors paved the way for electronics based on single dopants. Recently the spectrum of a single dopant was measured electrically by coupling two…
Zero-frequency noise in adiabatically driven, interacting quantum systems
Roman-Pascal Riwar, Janine Splettstoesser, Jürgen König
We investigate current-current correlations of adiabatic charge pumping through interacting quantum dots weakly coupled to reservoirs. To calculate the zero-frequency noise for a t…
Charge and spin pumping through a double quantum dot
Roman-Pascal Riwar, Janine Splettstoesser
We calculate adiabatic charge and spin pumping through a serial double quantum dot with strong Coulomb interaction, coupled to normal metal or ferromagnetic contacts. We use a real…
Transient dynamics of a molecular quantum dot with a vibrational degree of freedom
R. -P. Riwar, T. L. Schmidt
We investigate the transient effects occurring in a molecular quantum dot described by an Anderson-Holstein Hamiltonian which is instantly coupled to two fermionic leads biased by…