Related papers: High quality superconducting tantalum resonators with beta phase defects

High quality superconducting tantalum resonators with beta phase defects

URL: http://arxiv.org/abs/2502.17247v1
Date: Mon, 24 Feb 2025 15:25:23 GMT
Title: High quality superconducting tantalum resonators with beta phase defects
Authors: Ritika Dhundhwal, Haoran Duan, Lucas Brauch, Soroush Arabi, Dirk Fuchs, Amir-Abbas Haghighirad, Alexander Welle, Florentine Scharwaechter, Sudip Pal, Marc Scheffler, José Palomo, Zaki Leghtas, Anil Murani, Horst Hahn, Jasmin Aghassi-Hagmann, Christian Kübel, Wulf Wulfhekel, Ioan M. Pop, Thomas Reisinger,
Abstract summary: Coherence of superconducting transmon qubits has been shown to improve by forming qubit capacitor pads from $alpha$-tantalum.<n>We show resonators containing $beta$-phase tantalum in the form of inclusions near the metal-substrate interface with internal quality factors up to $(5.0 pm 2.5) times 106$ in the single photon regime.<n>Our results indicate that small concentrations of $beta$-phase can be beneficial, enhancing critical magnetic fields and potentially, for improving coherence in tantalum based superconducting circuits.
Score: 29.026630952383844
License: http://creativecommons.org/licenses/by/4.0/
Abstract: For practical superconducting quantum processors, orders of magnitude improvement in coherence is required, motivating efforts to optimize hardware design and explore new materials. Among the latter, the coherence of superconducting transmon qubits has been shown to improve by forming the qubit capacitor pads from $\alpha$-tantalum, avoiding the meta-stable $\beta$-phase that forms when depositing tantalum at room temperature, and has been previously identified to be a source of microwave losses. In this work, we show lumped element resonators containing $\beta$-phase tantalum in the form of inclusions near the metal-substrate interface with internal quality factors ($Q_\text{i}$) up to $(5.0 \pm 2.5) \times 10^6$ in the single photon regime. They outperform resonators with no sign of the $\beta$-phase in x-ray diffraction and thermal quasi-particle loss. Our results indicate that small concentrations of $\beta$-phase can be beneficial, enhancing critical magnetic fields and potentially, for improving coherence in tantalum based superconducting circuits.

Related papers

Quantum noise spectroscopy of superconducting critical dynamics and vortex fluctuations in a high-temperature cuprate [3.9724609654446703]
We introduce nitrogen-vacancy centers in diamond as a novel and powerful quantum sensing platform of superconducting materials.<n>We demonstrate the strengths of our approach by probing several low-energy phenomena in high-$T_c$ cuprate Bi$$Sr$$CaCu$$$O$_8+delta$ (BSCCO)<n>In the absence of an applied magnetic field, we find a sharp reduction in the NV relaxation time near the critical temperature $T_capprox90$K, attributed to supercurrent-fluctuation induced magnetic noise.
arXiv Detail & Related papers (2025-02-06T19:00:01Z)
Evidence of P-wave Pairing in K$_2$Cr$_3$As$_3$ Superconductors from Phase-sensitive Measurement [26.69408771617283]
We study a recently discovered family of superconductors, A$$Cr$_3$As$_3$ (A = K, Rb, Cs)<n>We fabricate superconducting quantum interference devices (SQUIDs) on exfoliated K$$Cr$_3$As$_3$, and perform the phase-sensitive measurement.<n>We observe that such SQUIDs exhibit a pronounced second-order harmonic component sin (2$pi$) in the current-phase relation, suggesting the admixture of 0- and $pi$-phase.
arXiv Detail & Related papers (2024-08-14T07:34:45Z)
Improved Coherence in Optically-Defined Niobium Trilayer Junction Qubits [45.786749852292246]
Niobium offers the benefit of increased operating temperatures and frequencies for superconducting devices. We revisit niobium trilayer junctions and fabricate all-niobium transmons using only optical lithography. We characterize devices in the microwave domain, measuring coherence times up to $62mu$s and an average qubit quality factor above $105$.
arXiv Detail & Related papers (2023-06-09T13:26:13Z)
Erasure qubits: Overcoming the $T_1$ limit in superconducting circuits [105.54048699217668]
amplitude damping time, $T_phi$, has long stood as the major factor limiting quantum fidelity in superconducting circuits. We propose a scheme for overcoming the conventional $T_phi$ limit on fidelity by designing qubits in a way that amplitude damping errors can be detected and converted into erasure errors.
arXiv Detail & Related papers (2022-08-10T17:39:21Z)
Enhancing the Coherence of Superconducting Quantum Bits with Electric Fields [62.997667081978825]
We show that qubit coherence can be improved by tuning defects away from the qubit resonance using an applied DC-electric field. We also discuss how local gate electrodes can be implemented in superconducting quantum processors to enable simultaneous in-situ coherence optimization of individual qubits.
arXiv Detail & Related papers (2022-08-02T16:18:30Z)
Compact superconducting microwave resonators based on Al-AlOx-Al capacitor [56.00511651498414]
resonators based on aluminum oxide -- aluminum ($mathrmAl/AlO_x/Al$) parallel-plate capacitors. The size of the resonators is only 0.04$mathrmmm2$, which is more than one order smaller than the typical size of coplanar resonators.
arXiv Detail & Related papers (2022-03-17T20:11:53Z)
Engineering the Radiative Dynamics of Thermalized Excitons with Metal Interfaces [58.720142291102135]
We analyze the emission properties of excitons in TMDCs near planar metal interfaces. We find suppression or enhancement of emission relative to the point dipole case by several orders of magnitude. nanoscale optical cavities are a viable pathway to generating long-lifetime exciton states in TMDCs.
arXiv Detail & Related papers (2021-10-11T19:40:24Z)
Ultrafast renormalization of the onsite Coulomb repulsion in a cuprate superconductor [8.775772298435337]
We use time-resolved x-ray absorption spectroscopy to demonstrate the light-induced renormalization of the Hubbard $U$ in a cuprate superconductor. We show that intense femtosecond laser pulses induce a substantial redshift of the upper Hubbard band, while leaving the Zhang-Rice singlet energy unaffected. Our demonstration of a dynamical Hubbard $U$ renormalization in a copper oxide paves the way to a novel strategy for the manipulation of superconductivity, magnetism, as well as to the realization of other long-range-ordered phases in light-driven quantum materials.
arXiv Detail & Related papers (2021-09-27T17:59:42Z)
Enhanced coherence of all-nitride superconducting qubits epitaxially grown on silicon substrate [2.3180219011095327]
We develop superconducting qubits based on NbN/AlN/NbN epitaxial Josephson junctions on silicon substrates. The all-nitride qubits have great advantages such as chemical stability against oxidation.
arXiv Detail & Related papers (2021-03-13T13:03:17Z)
Surpassing the resistance quantum with a geometric superinductor [0.0]
Superinductors have a characteristic impedance exceeding the resistance quantum $R_textQ approx 6.45textkOmega$ which leads to a suppression of ground state charge fluctuations. We present modeling, fabrication and characterization of 104 planar aluminum coil resonators with a characteristic impedance up to 30.9 $textkOmega$ at 5.6 GHz. Geometric superinductors are free of uncontrolled tunneling events and offer high, linearity and the ability to couple magnetically.
arXiv Detail & Related papers (2020-07-03T12:22:44Z)
Optimal coupling of HoW$_{10}$ molecular magnets to superconducting circuits near spin clock transitions [85.83811987257297]
We study the coupling of pure and magnetically diluted crystals of HoW$_10$ magnetic clusters to microwave superconducting coplanar waveguides. Results show that engineering spin-clock states of molecular systems offers a promising strategy to combine sizeable spin-photon interactions with a sufficient isolation from unwanted magnetic noise sources.
arXiv Detail & Related papers (2019-11-18T11:03:06Z)

This list is automatically generated from the titles and abstracts of the papers in this site.