245 citations · 1.7k across the 70 of their papers we have counts for
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Magnetic Fluctuations in Niobium Pentoxide
Y. Krasnikova, A. A. Murthy, F. Crisa +10
Using a spin-polarized muon beam we were able to capture magnetic dynamics in an amorphous niobium pentoxide thin film. Muons are used to probe internal magnetic fields produced by…
Exploration of Parameters That Affect High Field Q-Slope
K. Howard, Y. -K. Kim, D. Bafia +1
The onset of high field Q-slope (HFQS) around 25 MV/m prevents cavities in electropolished (EP) condition from reaching high quality factors at high gradients due to the precipitat…
The Collaborative Effects of Intrinsic and Extrinsic Impurities in Low RRR SRF Cavities
K. Howard, Y. -K. Kim, D. Bafia +1
The superconducting radio-frequency (SRF) community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. W…
HELEN: Traveling Wave SRF Linear Collider Higgs Factory
S. Belomestnykh, P. C. Bhat, A. Grassellino +7
Traveling wave SRF accelerating structures offer several advantages over the traditional standing wave structures: substantially lower and lower , ratios o…
Quasiparticle spectroscopy in technologically-relevant niobium using London penetration depth measurements
Sunil Ghimire, Kamal R. Joshi, Amlan Datta +10
London penetration depth was measured in niobium foils, thin films, single crystals, and superconducting radio-frequency (SRF) cavity pieces cut out from different places. The low-…
Phase-controlled improvement of photon lifetime in coupled superconducting cavities
Changqing Wang, Oleksandr S Melnychuk, Crispin Contreras-Martinez +9
High-quality cavities are crucial for various fundamental physical studies and applications. Here we find that by coupling two cavities directly or via a phase-tunable coupling cha…
First Direct Observation of Nanometer size Hydride Precipitations on Superconducting Niobium
Zu Hawn Sung, Arely Cano, Akshay Murthy +5
Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. At room temperature, hydrogen c…
Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium Surface Encapsulation
Mustafa Bal, Akshay A. Murthy, Shaojiang Zhu +37
We present a novel transmon qubit fabrication technique that yields systematic improvements in T relaxation times. We fabricate devices using an encapsulation strategy that inv…
Completely Positive Map for Noisy Driven Quantum Systems Derived by Keldysh Expansion
Ziwen Huang, Yunwei Lu, Anna Grassellino +3
Accurate modeling of decoherence errors in quantum processors is crucial for analyzing and improving gate fidelities. To increase the accuracy beyond that of the Lindblad dynamical…
Millikelvin measurements of permittivity and loss tangent of lithium niobate
Silvia Zorzetti, Changqing Wang, Ivan Gonin +5
Lithium Niobate is an electro-optic material with many applications in microwave signal processing, communication, quantum sensing, and quantum computing. In this letter, we presen…
New Exclusion Limit for Dark Photons from an SRF Cavity-Based Search (Dark SRF)
A. Romanenko, R. Harnik, A. Grassellino +11
We conduct the first ``light-shining-through-wall" (LSW) search for dark photons using two state-of-the-art high quality-factor superconducting radio frequency (SRF) cavities and r…