Fast universal control of a flux qubit via exponentially tunable wave-function overlap

• URL: http://arxiv.org/abs/2303.01102v2
• Date: Tue, 28 Nov 2023 11:07:36 GMT
• Title: Fast universal control of a flux qubit via exponentially tunable wave-function overlap
• Abstract summary: 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.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Fast, high fidelity control and readout of protected superconducting qubits are fundamentally challenging due to their inherent insensitivity. 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. One of the junctions is tunable, making it possible to control the barrier height and thus the level of protection. We analyze single- and two-qubit gate operations that rely on lowering the barrier. We show that this is a viable method that results in high fidelity gates as the non-computational states are not occupied during operations. Further, we show how the effective coupling to a readout resonator can be controlled by adjusting the externally applied flux while the DSFQ is protected from decaying into the readout resonator. Finally, we also study a double-loop gradiometric version of the DSFQ which is exponentially insensitive to variations in the global magnetic field, even when the loop areas are non-identical.

Related papers

• Flux-Activated Resonant Control of a Bosonic Quantum Memory [63.35373457838474]
  Bosonic circuit quantum electrodynamics (cQED) coherently control long-lived superconducting cavities.<n>We integrate an on-chip flux-control architecture with a long-lived bosonic memory housed in a 3D superconducting cavity.<n>We realize efficient arbitrary rotations between any pair of Fock levels in the memory.
  arXiv  Detail & Related papers  (2026-02-20T10:22:53Z)
• High-fidelity two-qubit gates with transmon qubits using bipolar flux pulses and tunable couplers [25.989599596628693]
  Scheme based on superconducting transmon qubits and control pulse delivery protocol.<n>We demonstrate a high-fidelity two-qubit gate with a performance of $99.5%$.<n>We confirm the scalability potential of the proposed scheme on a high-fidelity 4-qubit quantum processor.
  arXiv  Detail & Related papers  (2025-09-05T09:43:29Z)
• Robustness of longitudinal transmon readout to ionization [79.16635054977068]
  Multi-photon processes deteriorate the quantum non-demolition character of the dispersive readout in circuit QED. Alternative methods such as the longitudinal readout have been proposed. We show that fast, high-fidelity QND readout of transmon qubits is possible with longitudinal coupling.
  arXiv  Detail & Related papers  (2024-12-10T18:32:30Z)
• Protected Fluxonium Control with Sub-harmonic Parametric Driving [0.0]
  We show a novel control scheme for superconducting fluxonium qubits that eliminates qubit decay through the control channel. Adding a low-pass filter on the flux line allows for flux-biasing and at the same time coherently controlling the fluxonium qubit. We demonstrate coherent control with up to 11-photon sub-harmonic drives, highlighting the strong non-linearity of the fluxonium potential.
  arXiv  Detail & Related papers  (2024-10-01T08:27:19Z)
• Full Qubit Control in the NV$^-$ Ground State for Low Field or High Frequency Sensing [0.0]
  We present a scheme for the implementation of fast arbitrary qubit gates in the ground state of the negatively charged nitrogen-vacancy defect in diamond. The protocol is especially useful in the low-field regime and for high-frequency sensing applications.
  arXiv  Detail & Related papers  (2024-07-24T17:58:16Z)
• Self-correcting GKP qubit and gates in a driven-dissipative circuit [1.8960192929603623]
  We show that a self-correcting GKP qubit can be realized with a high-impedance LC circuit coupled to a resistor and a Josephson junction via a controllable switch. We show the qubit supports exponentially robust single-qubit Clifford gates, implemented via appropriate control of the switch, and readout/initialization via supercurrent measurement.
  arXiv  Detail & Related papers  (2024-05-09T10:51:48Z)
• Realization of two-qubit gates and multi-body entanglement states in an asymmetric superconducting circuits [3.9488862168263412]
  We propose a tunable fluxonium-transmon-transmon (FTT) cou pling scheme. The asymmetric structure composed of fluxonium and transmon will optimize the frequency space and form a high fidelity two-qubit quantum gate. We study the performance of this scheme by simulating the general single-qubit Xpi/2 gate and two-qubit (iSWAP) gate.
  arXiv  Detail & Related papers  (2024-04-12T08:44:21Z)
• Enhancing Dispersive Readout of Superconducting Qubits Through Dynamic Control of the Dispersive Shift: Experiment and Theory [47.00474212574662]
  A superconducting qubit is coupled to a large-bandwidth readout resonator. We show a beyond-state-of-the-art two-state-readout error of only 0.25,%$ in 100 ns integration time. The presented results are expected to further boost the performance of new and existing algorithms and protocols.
  arXiv  Detail & Related papers  (2023-07-15T10:30:10Z)
• Spectrum Breathing: Protecting Over-the-Air Federated Learning Against Interference [73.63024765499719]
  Mobile networks can be compromised by interference from neighboring cells or jammers. We propose Spectrum Breathing, which cascades-gradient pruning and spread spectrum to suppress interference without bandwidth expansion. We show a performance tradeoff between gradient-pruning and interference-induced error as regulated by the breathing depth.
  arXiv  Detail & Related papers  (2023-05-10T07:05:43Z)
• Qubit readouts enabled by qubit cloaking [49.1574468325115]
  Time-dependent drives play a crucial role in quantum computing efforts. They enable single-qubit control, entangling logical operations, as well as qubit readout. Qubit cloaking was introduced in Lled'o, Dassonneville, et al.
  arXiv  Detail & Related papers  (2023-05-01T15:58:25Z)
• 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)
• Multi-squeezed state generation and universal bosonic control via a driven quantum Rabi model [68.8204255655161]
  Universal control over a bosonic degree of freedom is key in the quest for quantum-based technologies. Here we consider a single ancillary two-level system, interacting with the bosonic mode of interest via a driven quantum Rabi model. We show that it is sufficient to induce the deterministic realization of a large class of Gaussian and non-Gaussian gates, which in turn provide universal bosonic control.
  arXiv  Detail & Related papers  (2022-09-16T14:18:53Z)
• High fidelity two-qubit gates on fluxoniums using a tunable coupler [47.187609203210705]
  Superconducting fluxonium qubits provide a promising alternative to transmons on the path toward large-scale quantum computing. A major challenge for multi-qubit fluxonium devices is the experimental demonstration of a scalable crosstalk-free multi-qubit architecture. Here, we present a two-qubit fluxonium-based quantum processor with a tunable coupler element.
  arXiv  Detail & Related papers  (2022-03-30T13:44:52Z)
• Dynamical sweet spot engineering via two-tone flux modulation of superconducting qubits [0.0]
  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.
  arXiv  Detail & Related papers  (2021-04-16T00:54:46Z)
• 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)
• Hardware-Encoding Grid States in a Non-Reciprocal Superconducting Circuit [62.997667081978825]
  We present a circuit design composed of a non-reciprocal device and Josephson junctions whose ground space is doubly degenerate and the ground states are approximate codewords of the Gottesman-Kitaev-Preskill (GKP) code. We find that the circuit is naturally protected against the common noise channels in superconducting circuits, such as charge and flux noise, implying that it can be used for passive quantum error correction.
  arXiv  Detail & Related papers  (2020-02-18T16:45:09Z)

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.