Broadband high-precision measurement of two-level-system loss using multiwavelength superconducting resonators
Cliff Chen, Shahriar Aghaeimeibodi, Yuki Sato, Matthew H. Matheny, Oskar Painter, Jiansong Gao
DOI 10.1103/2l7h-zn9s · Physical Review Applied
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
Two-level systems (TLSs) are known to be a dominant source of dissipation and decoherence in superconducting qubits. Superconducting resonators provide a convenient way to study TLS-induced loss due to easier design and fabrication in comparison with devices that include nonlinear elements such as Josephson junctions. However, precisely measuring TLS-induced loss in a resonator in the quantum regime is challenging due to low signal-to-noise ratio (SNR) and the temporal fluctuations of the TLS, leading to uncertainties of 20% or more in the loss measurement. To address these limitations, we develop a multiwavelength resonator device that extends the resonator length from a standard quarter wavelength λ/4 to Nλ/4, where N=37, at 6 GHz. This design provides two key advantages: the TLS-induced fluctuations are reduced by a factor of N due to spatial averaging over an increased number of independent TLSs, and the measurement SNR for a given intraresonator energy density increases by a factor of N. The multiwavelength resonator also has fundamental and harmonic resonances spanning a wide frequency range, allowing one to study the frequency dependence of TLS-induced loss. In this work we fabricate both multiwavelength and quarter-wave coplanar waveguide resonators formed from thin-film aluminum on a silicon substrate, and characterize their TLS properties at 10 and 200 mK. Our results show that the power-dependent TLS-induced loss measured from the Nλ/4 resonator agrees well with that measured from the λ/4 resonator, while achieving a fivefold reduction in measurement uncertainty due to TLS fluctuations, down to 5%. The Nλ/4 resonator also provides a measure of the fully unsaturated TLS-induced loss due to the increased measurement SNR at low intraresonator energy densities. Finally, measurements across seven harmonic resonances of the Nλ/4 resonator between 4 and 6.5 GHz reveal no frequency dependence in the TLS-induced loss over this range. These results highlight the benefits of the multiwavelength resonator approach for material development in superconducting quantum circuits.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Al Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Realizing a Circuit Analog of an Optomechanical System with Longitudinally Coupled Superconducting Resonators
similarity 0.95C. Eichler & J. R. Petta
Source status unknown — claims are unverified
Ultrastrong Tunable Coupler Between Superconducting LC Resonators
similarity 0.94T. Miyanaga et al.
Source status unknown — claims are unverified
Low-characteristic-impedance superconducting tadpole resonators in the sub-gigahertz regime
similarity 0.94Miika Rasola et al.
Source status unknown — claims are unverified
Rise and fall of shape resonances in thin films of BCS superconductors
similarity 0.94D. Valentinis et al.
Source status unknown — claims are unverified
Collective modes and their coupling to pair-breaking excitations in layered d-wave superconductors
similarity 0.93E. H. Hwang & S. Das Sarma
Source status unknown — claims are unverified
Finite-size effects in a nanowire strongly coupled to a thin superconducting shell
similarity 0.93Christopher Reeg et al.
Source status unknown — claims are unverified