papers

Publications (11)

quant-ph2024

Suppressing Counter-Rotating Errors for Fast Single-Qubit Gates with Fluxonium

David A. Rower, Leon Ding, Helin Zhang +12

Qubit decoherence unavoidably degrades the fidelity of quantum logic gates. Accordingly, realizing gates that are as fast as possible is a guiding principle for qubit control, nece…

quant-ph2026

Precision quantum simulation of magnon spectra and interactions

Trond I. Andersen, Nikita Astrakhantsev, Jeronimo Martinez +329

Quantum simulation promises to advance materials discovery by accurately simulating complex states of matter, their microscopic excitations, and macroscopic response functions. The…

quant-ph2021

Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler

Youngkyu Sung, Leon Ding, Jochen Braumüller +14

High-fidelity two-qubit gates at scale are a key requirement to realize the full promise of quantum computation and simulation. The advent and use of coupler elements to tunably co…

quant-ph2025

ZZ-Free Two-Transmon CZ Gate Mediated by a Fluxonium Coupler

Junyoung An, Helin Zhang, Qi Ding +19

Eliminating residual ZZ interactions in a two-qubit system is essential for reducing coherent errors during quantum operations. In a superconducting circuit platform, coupling two…

quant-ph2023

High-Fidelity, Frequency-Flexible Two-Qubit Fluxonium Gates with a Transmon Coupler

Leon Ding, Max Hays, Youngkyu Sung +16

We propose and demonstrate an architecture for fluxonium-fluxonium two-qubit gates mediated by transmon couplers (FTF, for fluxonium-transmon-fluxonium). Relative to architectures…

quant-ph2024

Dephasing in Fluxonium Qubits from Coherent Quantum Phase Slips

Mallika T. Randeria, Thomas M. Hazard, Agustin Di Paolo +12

Phase slips occur across all Josephson junctions (JJs) at a rate that increases with the impedance of the junction. In superconducting qubits composed of JJ-array superinductors --…

cond-mat.mes-hall2023

Evolution of Flux Noise in Superconducting Qubits with Weak Magnetic Fields

David A. Rower, Lamia Ateshian, Lauren H. Li +18

The microscopic origin of magnetic flux noise in superconducting circuits has remained an open question for several decades despite extensive experimental and theoretical inv…

quant-ph2020

Characterizing and optimizing qubit coherence based on SQUID geometry

Jochen Braumüller, Leon Ding, Antti Vepsäläinen +12

The dominant source of decoherence in contemporary frequency-tunable superconducting qubits is 1/ flux noise. To understand its origin and find ways to minimize its impact, we s…

quant-ph2025

Temperature and Magnetic-Field Dependence of Energy Relaxation in a Fluxonium Qubit

Lamia Ateshian, Max Hays, David A. Rower +14

Noise from material defects at device interfaces is known to limit the coherence of superconducting circuits, yet our understanding of the defect origins and noise mechanisms remai…

quant-ph2026

Characterization and Comparison of Energy Relaxation in Fluxonium Qubits

Kate Azar, Lamia Ateshian, Mallika T. Randeria +19

Fluxonium superconducting qubits have demonstrated long coherence times and high single- and two-qubit gate fidelities, making them a favorable building block for superconducting q…

quant-ph2023

Probing entanglement across the energy spectrum of a hard-core Bose-Hubbard lattice

Amir H. Karamlou, Ilan T. Rosen, Sarah E. Muschinske +16

Entanglement and its propagation are central to understanding a multitude of physical properties of quantum systems. Notably, within closed quantum many-body systems, entanglement…