Materials challenges and opportunities for quantum computing hardware

NP De Leon, KM Itoh, D Kim, KK Mehta, TE Northup… - Science, 2021‏ - science.org
BACKGROUND The past two decades have seen intense efforts aimed at building quantum
computing hardware with the potential to solve problems that are intractable on classical …

Towards understanding two-level-systems in amorphous solids: insights from quantum circuits

C Müller, JH Cole, J Lisenfeld - Reports on Progress in Physics, 2019‏ - iopscience.iop.org
Amorphous solids show surprisingly universal behaviour at low temperatures. The
prevailing wisdom is that this can be explained by the existence of two-state defects within …

Surpassing millisecond coherence in on chip superconducting quantum memories by optimizing materials and circuit design

S Ganjam, Y Wang, Y Lu, A Banerjee, CU Lei… - Nature …, 2024‏ - nature.com
The performance of superconducting quantum circuits for quantum computing has advanced
tremendously in recent decades; however, a comprehensive understanding of relaxation …

Disentangling losses in tantalum superconducting circuits

KD Crowley, RA McLellan, A Dutta, N Shumiya… - Physical Review X, 2023‏ - APS
Superconducting qubits are a leading system for realizing large-scale quantum processors,
but overall gate fidelities suffer from coherence times limited by microwave dielectric loss …

High-cooperativity cavity QED with magnons at microwave frequencies

M Goryachev, WG Farr, DL Creedon, Y Fan… - Physical Review …, 2014‏ - APS
Using a submillimeter-sized YIG (yttrium-iron-garnet) sphere mounted in a magnetic-field-
focusing cavity, we demonstrate an ultrahigh cooperativity of 1 0 5 between magnon and …

[HTML][HTML] Surface participation and dielectric loss in superconducting qubits

C Wang, C Axline, YY Gao, T Brecht, Y Chu… - Applied Physics …, 2015‏ - pubs.aip.org
We study the energy relaxation times (T 1) of superconducting transmon qubits in 3D
cavities as a function of dielectric participation ratios of material surfaces. This surface …

Material matters in superconducting qubits

CE Murray - Materials Science and Engineering: R: Reports, 2021‏ - Elsevier
The progress witnessed within the field of quantum computing has been enabled by the
identification and understanding of interactions between the state of the quantum bit (qubit) …

Planar superconducting resonators with internal quality factors above one million

A Megrant, C Neill, R Barends, B Chiaro… - Applied Physics …, 2012‏ - pubs.aip.org
We describe the fabrication and measurement of microwave coplanar waveguide resonators
with internal quality factors above 10 7 at high microwave powers and over 10 6 at low …

Improved superconducting qubit coherence using titanium nitride

JB Chang, MR Vissers, AD Córcoles… - Applied Physics …, 2013‏ - pubs.aip.org
We demonstrate enhanced relaxation and dephasing times of transmon qubits, up to∼ 60 μ
s⁠, by fabricating the interdigitated shunting capacitors using titanium nitride (TiN) …

Precision measurement of the microwave dielectric loss of sapphire in the quantum regime with parts-per-billion sensitivity

AP Read, BJ Chapman, CU Lei, JC Curtis, S Ganjam… - Physical Review …, 2023‏ - APS
Dielectric loss is known to limit state-of-the-art superconducting qubit lifetimes. Recent
experiments imply upper bounds on bulk dielectric loss tangents on the order of 100 parts …