7 citations · 18 across the 14 of their papers we have counts for
14 papers
Evidence for a low-gap component in compressively stressed niobium thin films
J. T. Paustian, Maciej Olszewski, Kiichi Okubo +6
We investigate the microwave response of sputtered Nb films as a function of biaxial film stress. Although transport measurements show nearly identical superconducting transition t…
Fabrication-free assessment of microwave losses in germanium-based dielectrics and superconductors
Haoran Lu, Kushagra Aggarwal, Xiangqin Wang +10
We present a flip-chip-based sensing scheme to measure effective microwave losses associated with target materials for quantum technologies, without requiring any device fabricatio…
High-Q superconducting microwave resonators using MBE titanium nitride
Anand Ithepalli, Haoran Lu, Eegene Clara Chung +9
Using molecular beam epitaxy, we have realized thin films of titanium nitride (TiN) on c-plane sapphire that exhibit the lowest observed full-width at half maximum X-ray rocking cu…
Resist-free shadow deposition using silicon trenches for Josephson junctions in superconducting qubits
Tathagata Banerjee, Stephen Daniel Funni, Saswata Roy +2
Superconducting qubit fabrication innovations continue to be explored to achieve higher performance. Despite improvements to base layer fabrication and processing, resist-based Jos…
Fabrication effects on Niobium oxidation and surface contamination in Niobium-metal bilayers using X-ray photoelectron spectroscopy
Tathagata Banerjee, Maciej W. Olszewski, Valla Fatemi
Superconducting resonators and qubits are limited by dielectric losses from surface oxides. Surface oxides are mitigated through various strategies such as the addition of a metal…
Krypton-sputtered tantalum films for scalable high-performance quantum devices
Maciej W. Olszewski, Lingda Kong, Simon Reinhardt +9
Superconducting qubits based on tantalum (Ta) thin films have demonstrated the highest-performing microwave resonators and qubits. This makes Ta an attractive material for supercon…
Spectroscopy and Coherent Control of Two-Level System Defect Ensembles Using a Broadband 3D Waveguide
Qianxu Wang, Juan S. Salcedo-Gallo, Salil Bedkihal +4
Defects in solid-state materials play a central role in determining coherence, stability, and performance in quantum technologies. Although narrowband techniques can probe specific…
Active-Learning Inspired Theory-Experiment Loop Approach for Management of Material Defects: Application to Superconducting Qubits
Sarvesh Chaudhari, Cristóbal Méndez, Rushil Choudhary +11
Surface oxides are associated with two-level systems (TLSs) that degrade the performance of niobium-based superconducting quantum computing devices. To address this, we introduce a…
Low barrier ZrO-based Josephson junctions
Jaehong Choi, Maciej Olszewski, Luojia Zhang +8
The Josephson junction is a crucial element in superconducting devices, and niobium is a promising candidate for the superconducting material due to its large energy gap relative t…
Mixed spin-boson coupling for qubit readout with suppressed residual shot-noise dephasing
Jinlun Hu, Antonio L. R. Manesco, André Melo +3
Direct dipole coupling between a two-level system and a bosonic mode describes the interactions present in a wide range of physical platforms. In this work, we study a coupling tha…
Low-loss Nb on Si superconducting resonators from a dual-use spintronics deposition chamber and with acid-free post-processing
Maciej W. Olszewski, Jadrien T. Paustian, Tathagata Banerjee +13
Magnetic impurities are known to degrade superconductivity. For this reason, physical vapor deposition chambers that have previously been used for magnetic materials have generally…
Growth and characterization of single crystal cubic TaN and hexagonal TaN films on c-plane Sapphire
Anand Ithepalli, Amit Rohan Rajapurohita, Arjan Singh +7
Two single crystal phases of tantalum nitride were stabilized on c-plane sapphire using molecular beam epitaxy. The phases were identified to be -TaN with a rocksalt cubic struc…
Impact of etches on thin-film single-crystal niobium resonators
H. Wang, T. Banerjee, T. G. Farinha +4
A single crystal niobium thin film was grown using molecular beam epitaxy on a c-plane sapphire wafer. Several samples were fabricated into dc resistivity test devices and coplanar…
Molecular beam epitaxy growth of superconducting tantalum germanide
Patrick J. Strohbeen, Tathagata Banerjee, Aurelia M. Brook +7
Developing new material platforms for use in superconductor-semiconductor hybrid structures is desirable due to limitations caused by intrinsic microwave losses present in commonly…