Dynamical sweet spot engineering via two-tone flux modulation of superconducting qubits

• URL: http://arxiv.org/abs/2104.07835v1
• Date: Fri, 16 Apr 2021 00:54:46 GMT
• Title: Dynamical sweet spot engineering via two-tone flux modulation of superconducting qubits
• Authors: Joseph A. Valery, Shoumik Chowdhury, Glenn Jones, and Nicolas Didier
• Abstract summary: We experimentally demonstrate that two-tone flux modulation can be used to create a continuum of dynamical sweet spots. The ability to use flux control to freely select qubit frequencies while maintaining qubit coherence represents an important step forward in the robustness and scalability of near-term superconducting qubit devices.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Current superconducting quantum processors require strategies for coping with material defects and imperfect parameter targeting in order to scale up while maintaining high performance. To that end, in-situ control of qubit frequencies with magnetic flux can be used to avoid spurious resonances. However, increased dephasing due to 1/f flux noise limits performance at all of these operating points except for noise-protected sweet spots, which are sparse under DC flux bias and monochromatic flux modulation. Here we experimentally demonstrate that two-tone flux modulation can be used to create a continuum of dynamical sweet spots, greatly expanding the range of qubit frequencies achievable while first-order insensitive to slow flux noise. To illustrate some advantages of this flexibility, we use bichromatic flux control to reduce the error rates and gate times of parametric entangling operations between transmons. Independent of gate scheme, the ability to use flux control to freely select qubit frequencies while maintaining qubit coherence represents an important step forward in the robustness and scalability of near-term superconducting qubit devices.

Related papers

• Fast universal control of a flux qubit via exponentially tunable wave-function overlap [0.0]
  We propose a flux qubit variation which enjoys a tunable level of protection against relaxation to resolve this outstanding issue. Our qubit design, the double-shunted flux qubit (DSFQ), realizes a generic double-well potential through its three junction ring geometry.
  arXiv  Detail & Related papers  (2023-03-02T09:33:40Z)
• Autonomous coherence protection of a two-level system in a fluctuating environment [68.8204255655161]
  We re-examine a scheme originally intended to remove the effects of static Doppler broadening from an ensemble of non-interacting two-level systems (qubits) We demonstrate that this scheme is far more powerful and can also protect a single (or even an ensemble) qubit's energy levels from noise which depends on both time and space.
  arXiv  Detail & Related papers  (2023-02-08T01:44:30Z)
• Stabilizing and improving qubit coherence by engineering noise spectrum of two-level systems [52.77024349608834]
  Superconducting circuits are a leading platform for quantum computing. Charge fluctuators inside amorphous oxide layers contribute to both low-frequency $1/f$ charge noise and high-frequency dielectric loss. We propose to mitigate those harmful effects by engineering the relevant TLS noise spectral densities.
  arXiv  Detail & Related papers  (2022-06-21T18:37:38Z)
• Weakly Flux-Tunable Superconducting Qubit [0.0]
  We develop a coherent, flux-tunable, transmon-like qubit with a frequency tunability range as small as 43 MHz. Such a weakly tunable qubit is useful for avoiding frequency collisions in a large lattice while limiting its susceptibility to flux noise.
  arXiv  Detail & Related papers  (2022-03-08T15:49:48Z)
• A superconducting qubit with noise-insensitive plasmon levels and decay-protected fluxon states [0.0]
  inductively shunted transmon (IST) is a superconducting qubit with exponentially suppressed fluxon transitions and a plasmon spectrum approximating that of the transmon. We realize IST qubits deep in the transmon limit where the large geometric inductance acts as a mere perturbation.
  arXiv  Detail & Related papers  (2022-02-28T16:11:55Z)
• Learning Noise via Dynamical Decoupling of Entangled Qubits [49.38020717064383]
  Noise in entangled quantum systems is difficult to characterize due to many-body effects involving multiple degrees of freedom. We develop and apply multi-qubit dynamical decoupling sequences that characterize noise that occurs during two-qubit gates.
  arXiv  Detail & Related papers  (2022-01-26T20:22:38Z)
• Optimization of the resonator-induced phase gate for superconducting qubits [0.0]
  We study the physics of weakly anharmonic transmon qubits coupled to linear resonators. We show this type of leakage can be substantially suppressed using very weakly anharmonic transmons.
  arXiv  Detail & Related papers  (2021-10-04T21:27:02Z)
• Superconducting coupler with exponentially large on-off ratio [68.8204255655161]
  Tunable two-qubit couplers offer an avenue to mitigate errors in multiqubit superconducting quantum processors. Most couplers operate in a narrow frequency band and target specific couplings, such as the spurious $ZZ$ interaction. We introduce a superconducting coupler that alleviates these limitations by suppressing all two-qubit interactions with an exponentially large on-off ratio.
  arXiv  Detail & Related papers  (2021-07-21T03:03:13Z)
• Hardware-Efficient Microwave-Activated Tunable Coupling Between Superconducting Qubits [0.0]
  We realize a tunable $ZZ$ interaction between two transmon qubits with fixed frequencies and fixed coupling. Because both transmons are driven, it is resilient to microwave crosstalk. We apply this interaction to implement a controlled phase (CZ) gate with a gate fidelity of $99.43(1)%$ as measured by cycle benchmarking.
  arXiv  Detail & Related papers  (2021-05-12T01:06:08Z)
• Stabilization of Qubit Relaxation Rates by Frequency Modulation [68.8204255655161]
  Temporal, spectral, and sample-to-sample fluctuations in coherence properties of qubits form an outstanding challenge for the development of upscaled fault-tolerant quantum computers. A ubiquitous source for these fluctuations in superconducting qubits is a set of atomic-scale defects with a two-level structure. We show that frequency modulation of a qubit or, alternatively, of the two-level defects, leads to averaging of the qubit relaxation rate over a wide interval of frequencies.
  arXiv  Detail & Related papers  (2021-04-08T11:32:03Z)
• Universal non-adiabatic control of small-gap superconducting qubits [47.187609203210705]
  We introduce a superconducting composite qubit formed from two capacitively coupled transmon qubits. We control this low-frequency CQB using solely baseband pulses, non-adiabatic transitions, and coherent Landau-Zener interference. This work demonstrates that universal non-adiabatic control of low-frequency qubits is feasible using solely baseband pulses.
  arXiv  Detail & Related papers  (2020-03-29T22:48:34Z)

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

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.