Implementation of a Transmon Qubit Using Superconducting Granular Aluminum
Patrick Winkel, Kiril Borisov, Lukas Grünhaupt, Dennis Rieger, Martin Spiecker, Francesco Valenti, Alexey V. Ustinov, Wolfgang Wernsdorfer, Ioan M. Pop
DOI 10.1103/PhysRevX.10.031032 · Physical Review X
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
The high kinetic inductance offered by granular aluminum (grAl) has recently been employed for linear inductors in superconducting high-impedance qubits and kinetic inductance detectors. Because of its large critical current density compared to typical Josephson junctions, its resilience to external magnetic fields, and its low dissipation, grAl may also provide a robust source of nonlinearity for strongly driven quantum circuits, topological superconductivity, and hybrid systems. Having said that, can the grAl nonlinearity be sufficient to build a qubit? Here we show that a small grAl volume (10×200×500 nm3) shunted by a thin film aluminum capacitor results in a microwave oscillator with anharmonicity α two orders of magnitude larger than its spectral linewidth Γ01, effectively forming a transmon qubit. With increasing drive power, we observe several multiphoton transitions starting from the ground state, from which we extract α=2π×4.48 MHz. Resonance fluorescence measurements of the |0⟩→|1⟩ transition yield an intrinsic qubit linewidth γ=2π×10 kHz, corresponding to a lifetime of 16 μs, as confirmed by pulsed time-domain measurements. This linewidth remains below 2π×150 kHz for in-plane magnetic fields up to ∼70 mT.
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. | 1.9 | Pressure not reported | unknown |
Similar papers
Measurements of Quasiparticle Tunneling Dynamics in a Band-Gap-Engineered Transmon Qubit
similarity 0.93L. Sun et al.
Source status unknown — claims are unverified
Implementation of a transmon qubit using superconducting granular aluminum
similarity 0.93Patrick Winkel et al. · 2019 · arXiv:1911.02333
Source status unknown — claims are unverified
Electrodynamics of granular aluminum from superconductor to insulator: Observation of collective superconducting modes
similarity 0.93F. Levy-Bertrand et al.
Source status unknown — claims are unverified
Spin-Polarized Tunneling Study of s−f Exchange in Superconductors
similarity 0.93J. E. Tkaczyk & P. M. Tedrow
Source status unknown — claims are unverified
Microscopic charging and in-gap states in superconducting granular aluminum
similarity 0.93Fang Yang et al.
Source status unknown — claims are unverified
Loss Mechanisms and Quasiparticle Dynamics in Superconducting Microwave Resonators Made of Thin-Film Granular Aluminum
similarity 0.93Lukas Grünhaupt et al.
Source status unknown — claims are unverified