Impact of Josephson junction array modes on fluxonium readout

• URL: http://arxiv.org/abs/2412.14788v2
• Date: Wed, 08 Jan 2025 20:07:04 GMT
• Title: Impact of Josephson junction array modes on fluxonium readout
• Authors: Shraddha Singh, Gil Refael, Aashish Clerk, Emma Rosenfeld,
• Abstract summary: We theoretically analyze measurement-induced state transitions (MIST) during the dispersive readout of a fluxonium qubit. We show that these new kinds of MIST processes can be relevant when using realistic circuit parameters and relatively low readout drive powers.
• Score: 0.0
• License:
• Abstract: Dispersive readout of superconducting qubits is often limited by readout-drive-induced transitions between qubit levels. While there is a growing understanding of such effects in transmon qubits, the case of highly nonlinear fluxonium qubits is more complex. We theoretically analyze measurement-induced state transitions (MIST) during the dispersive readout of a fluxonium qubit. We focus on a new mechanism: a simultaneous transition/excitation involving the qubit and an internal mode of the Josephson junction array in the fluxonium circuit. Using an adiabatic Floquet approach, we show that these new kinds of MIST processes can be relevant when using realistic circuit parameters and relatively low readout drive powers. They also contribute to excess qubit dephasing even after a measurement is complete. In addition to outlining basic mechanisms, we also investigate the dependence of such transitions on the circuit parameters. We find that with a judicious choice of frequency allocations or coupling strengths, these parasitic processes can most likely be avoided.

Related papers

• 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)
• Probing Site-Resolved Current in Strongly Interacting Superconducting Circuit Lattices [0.0]
  Transport measurements are fundamental for understanding condensed matter phenomena, from superconductivity to the fractional quantum Hall effect. Here we demonstrate the measurement of in-situ particle current in a superconducting circuit lattice and apply it to study transport in both coherent and bath-coupled lattices.
  arXiv  Detail & Related papers  (2024-03-18T17:08:04Z)
• Ultrafast Superconducting Qubit Readout with the Quarton Coupler [1.4571671739637337]
  State-of-the-art readout is based on a dispersive cross-Kerr coupling between a qubit and its readout resonator. We present a new scheme that uses the quarton coupler to facilitate a large (greater than 250 MHz) cross-Kerr between a transmon qubit and its readout resonator. Full master equation simulations show a 5 ns readout time with greater than 99% readout and QND fidelity.
  arXiv  Detail & Related papers  (2024-02-24T00:39:35Z)
• Flux-pulse-assisted Readout of a Fluxonium Qubit [0.0]
  We propose to exploit the features in the dispersive shift to improve qubit readout. Specifically, we report on theoretical simulations showing improved readout times and error rates by performing the readout at a flux bias point. We expand the scheme to include different error channels, and show that with an integration time of 155 ns, flux-pulse-assisted readout offers about 5 times improvement in the signal to noise ratio.
  arXiv  Detail & Related papers  (2023-09-29T14:43:43Z)
• 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)
• Reminiscence of classical chaos in driven transmons [117.851325578242]
  We show that even off-resonant drives can cause strong modifications to the structure of the transmon spectrum rendering a large part of it chaotic. Results lead to a photon number threshold characterizing the appearance of chaos-induced quantum demolition effects.
  arXiv  Detail & Related papers  (2022-07-19T16:04:46Z)
• 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)
• Designing Kerr Interactions for Quantum Information Processing via Counterrotating Terms of Asymmetric Josephson-Junction Loops [68.8204255655161]
  static cavity nonlinearities typically limit the performance of bosonic quantum error-correcting codes. Treating the nonlinearity as a perturbation, we derive effective Hamiltonians using the Schrieffer-Wolff transformation. Results show that a cubic interaction allows to increase the effective rates of both linear and nonlinear operations.
  arXiv  Detail & Related papers  (2021-07-14T15:11:05Z)
• Excitation dynamics in inductively coupled fluxonium circuits [0.0]
  We propose a near-term quantum simulator based on the fluxonium qubits inductively coupled to form a chain. This system provides long coherence time, large anharmonicity, and strong coupling, making it suitable to study Ising spin models.
  arXiv  Detail & Related papers  (2021-04-07T17:55:53Z)
• Coherent superconducting qubits from a subtractive junction fabrication process [48.7576911714538]
  Josephson tunnel junctions are the centerpiece of almost any superconducting electronic circuit, including qubits. In recent years, sub-micron scale overlap junctions have started to attract attention. This work paves the way towards a more standardized process flow with advanced materials and growth processes, and constitutes an important step for large scale fabrication of superconducting quantum circuits.
  arXiv  Detail & Related papers  (2020-06-30T14:52:14Z)
• 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.