157 citations · 333 across the 14 of their papers we have counts for
15 papers
Superconducting circuits host two-level systems with lifetimes exceeding one second
Mathieu Féchant, Phillip Lenhard, Nicolas Gosling +5
Understanding the microscopic environment of superconducting qubits is a central challenge for quantum technologies. Parasitic two-level systems (TLSs) of various microscopic origi…
Double-Pumped Kerr Parametric Amplifier Beyond the Gain-Bandwidth Limit
Nicolas Zapata, Najmeh Etehadi Abari, Mitchell Field +5
Superconducting standingwave parametric amplifiers are crucial for the readout of microwave quantum devices. Despite significant improvements in recent years, the need to operat…
Quantum Coherence in Superconducting Vortex States
Ameya Nambisan, Simon Günzler, Dennis Rieger +13
Abrikosov vortices, where the superconducting gap is completely suppressed in the core, are dissipative, semi-classical entities that impact applications from high-current-density…
Enabling full localization of qubits and gates with a multi-mode coupler
Zhongyi Jiang, Simon Geisert, Sören Ihssen +2
Tunable couplers are a key building block of superconducting quantum processors, enabling high on-off ratios for two-qubit entangling interactions. While qubit-qubit interaction ca…
On-chip stencil lithography for superconducting qubits
Roudy Hanna, Sören Ihssen, Simon Geisert +22
Improvements in circuit design and more recently in materials and surface cleaning have contributed to a rapid development of coherent superconducting qubits. However, organic resi…
Offset Charge Dependence of Measurement-Induced Transitions in Transmons
Mathieu Féchant, Marie Frédérique Dumas, Denis Bénâtre +9
A key challenge in achieving scalable fault tolerance in superconducting quantum processors is readout fidelity, which lags behind one- and two-qubit gate fidelity. A major limitat…
Low crosstalk modular flip-chip architecture for coupled superconducting qubits
Soeren Ihssen, Simon Geisert, Gabriel Jauma +10
We present a flip-chip architecture for an array of coupled superconducting qubits, in which circuit components reside inside individual microwave enclosures. In contrast to other…
Thermalization of a flexible microwave stripline measured by a superconducting qubit
Patrick Paluch, Martin Spiecker, Nicolas Gosling +6
With the demand for scalable cryogenic microwave circuitry continuously rising, recently developed flexible microwave striplines offer the tantalyzing perspective of increasing the…
Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors
Marián Janík, Kevin Roux, Carla Borja Espinosa +11
High kinetic inductance superconductors are gaining increasing interest for the realisation of qubits, amplifiers and detectors. Moreover, thanks to their high impedance, quantum b…
Pure kinetic inductance coupling for cQED with flux qubits
Simon Geisert, Soeren Ihssen, Patrick Winkel +11
We demonstrate a qubit-readout architecture where the dispersive coupling is entirely mediated by a kinetic inductance. This allows us to engineer the dispersive shift of the reado…
Granular Aluminum Parametric Amplifier for Low-Noise Measurements in Tesla Fields
Nicolas Zapata, Ivan Takmakov, Simon Günzler +8
Josephson junction parametric amplifiers have become essential tools for microwave quantum circuit readout with minimal added noise. Even after improving at an impressive rate in t…
Fano Interference in Microwave Resonator Measurements
D. Rieger, S. Günzler, M. Spiecker +3
Resonator measurements are a simple but powerful tool to characterize a material's microwave response. The losses of a resonant mode are quantified by its internal quality factor $…
Superconducting granular aluminum resonators resilient to magnetic fields up to 1 Tesla
K. Borisov, D. Rieger, P. Winkel +8
High kinetic inductance materials constitute a valuable resource for superconducting quantum circuits and hybrid architectures. Superconducting granular aluminum (grAl) reaches kin…
Circuit Quantum Electrodynamics of Granular Aluminum Resonators
N. Maleeva, L. Grünhaupt, T. Klein +12
The introduction of crystalline defects or dopants can give rise to so-called "dirty superconductors", characterized by reduced coherence length and quasiparticle mean free path. I…
Bistability in a Mesoscopic Josephson Junction Array Resonator
P. R. Muppalla, O. Gargiulo, S. I. Mirzaei +5
We present an experimental investigation of stochastic switching of a bistable Josephson junctions array resonator with a resonance frequency in the GHz range. As the device is in…