Related papers: Non-degenerate noise-resilient superconducting qubit

Non-degenerate noise-resilient superconducting qubit

URL: http://arxiv.org/abs/2502.15459v1
Date: Fri, 21 Feb 2025 13:34:31 GMT
Title: Non-degenerate noise-resilient superconducting qubit
Authors: Max Hays, Junghyun Kim, William D. Oliver,
Abstract summary: We propose a superconducting qubit based on engineering the first and second harmonics of the Josephson energy and phase relation.<n>By constructing a circuit such that $E_J2$ is negative and $|E_J1| ll |E_J2|$, we create a periodic potential with two non-degenerate minima.<n>The qubit, which we dub "harmonium", is formed from the lowest-energy states of each minimum.
Score: 0.531628684262717
License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abstract: We propose a superconducting qubit based on engineering the first and second harmonics of the Josephson energy and phase relation $E_{J1}\cos \varphi$ and $E_{J2}\cos 2\varphi$. By constructing a circuit such that $E_{J2}$ is negative and $|E_{J1}| \ll |E_{J2}|$, we create a periodic potential with two non-degenerate minima. The qubit, which we dub "harmonium", is formed from the lowest-energy states of each minimum. Bit-flip protection of the qubit arises due to the localization of each qubit state to their respective minima, while phase-flip protection can be understood by considering the circuit within the Born-Oppenheimer approximation. We demonstrate with time-domain simulations that single- and two-qubit gates can be performed in approximately one hundred nanoseconds. Finally, we compute the qubit coherence times using numerical diagonalization of the complete circuit in conjunction with state-of-the-art noise models. We estimate out-of-manifold heating times on the order of milliseconds, which can be treated as erasure errors using conventional dispersive readout. We estimate pure-dephasing times on the order of many tens of milliseconds, and bit-flip times on the order of seconds.

Related papers

Simulation of a rapid qubit readout dependent on the transmission of a single fluxon [0.0]
We show a proposed device that gives readout of a fluxonium qubit using a ballistic fluxon with an estimated readout time of less than 1 nanosecond. We find that the device can exhibit single-shot readout of a qubit -- one qubit state leads to a single dynamical bounce at the interface and fluxon reflection, and the other qubit state leads to a couple of bounces at the interface and fluxon transmission.
arXiv Detail & Related papers (2025-04-26T13:04:00Z)
Fast gates for bit-flip protected superconducting qubits [0.0]
We introduce a qubit architecture with real-time tunable bit-flip protection. We show that base-band flux-pulses of around 10 ns are sufficient to realize a universal set of high-fidelity single- and two-qubit gates.
arXiv Detail & Related papers (2025-04-07T08:03:19Z)
On the Constant Depth Implementation of Pauli Exponentials [49.48516314472825]
We decompose arbitrary exponentials into circuits of constant depth using $mathcalO(n)$ ancillae and two-body XX and ZZ interactions. We prove the correctness of our approach, after introducing novel rewrite rules for circuits which benefit from qubit recycling.
arXiv Detail & Related papers (2024-08-15T17:09:08Z)
Coherent Control of the Fine-Structure Qubit in a Single Alkaline-Earth Atom [0.7033719572603241]
Raman coupling of qubit states promises rapid single-qubit rotations on par with the fast Rydberg-mediated two-body gates. We demonstrate preparation, read-out, and coherent control of the qubit. Our work opens the door for a so far unexplored qubit encoding concept for neutral atom based quantum computing.
arXiv Detail & Related papers (2024-01-19T13:22:27Z)
Cat-qubit-inspired gate on cos($2\theta$) qubits [77.34726150561087]
We introduce a single-qubit $Z$ gate inspired by the noise-bias preserving gate of the Kerr-cat qubit. This scheme relies on a $pi$ rotation in phase space via a beamsplitter-like transformation between a qubit and ancilla qubit.
arXiv Detail & Related papers (2023-04-04T23:06:22Z)
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)
Demonstration of the Two-Fluxonium Cross-Resonance Gate [1.8568045743509223]
Current implementations of two-qubit gates compromise fluxonium's coherence properties. We realize a fast all-microwave cross-resonance gate between two capacitively-coupled fluxoniums. Our results project a possible pathway towards reducing the two-qubit error rate below $10-4$ with present-day technologies.
arXiv Detail & Related papers (2022-04-25T17:59:17Z)
Unimon qubit [42.83899285555746]
Superconducting qubits are one of the most promising candidates to implement quantum computers. Here, we introduce and demonstrate a superconducting-qubit type, the unimon, which combines the desired properties of high non-linearity, full insensitivity to dc charge noise, insensitivity to flux noise, and a simple structure consisting only of a single Josephson junction in a resonator.
arXiv Detail & Related papers (2022-03-11T12:57:43Z)
Random quantum circuits transform local noise into global white noise [118.18170052022323]
We study the distribution over measurement outcomes of noisy random quantum circuits in the low-fidelity regime. For local noise that is sufficiently weak and unital, correlations (measured by the linear cross-entropy benchmark) between the output distribution $p_textnoisy$ of a generic noisy circuit instance shrink exponentially. If the noise is incoherent, the output distribution approaches the uniform distribution $p_textunif$ at precisely the same rate.
arXiv Detail & Related papers (2021-11-29T19:26:28Z)
Random quantum circuits anti-concentrate in log depth [118.18170052022323]
We study the number of gates needed for the distribution over measurement outcomes for typical circuit instances to be anti-concentrated. Our definition of anti-concentration is that the expected collision probability is only a constant factor larger than if the distribution were uniform. In both the case where the gates are nearest-neighbor on a 1D ring and the case where gates are long-range, we show $O(n log(n)) gates are also sufficient.
arXiv Detail & Related papers (2020-11-24T18:44:57Z)
Characterization of multi-level dynamics and decoherence in a high-anharmonicity capacitively shunted flux circuit [0.0]
We present a three-Josephson-junction superconducting circuit with three large capacitors as a qubit. The circuit shows long energy-relaxation times, order of the qubit, and a spin-echo dephaing time. These results demonstrate potential use for fastsecond-time-scale nano-scale quantum logic.
arXiv Detail & Related papers (2020-08-03T00:28:43Z)
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)
Non-degenerate parametric amplifiers based on dispersion engineered Josephson junction arrays [0.0]
We show the continuous detection of quantum jumps of a transmon qubit with 90% fidelity in state discrimination. A single amplifier device could potentially cover the entire frequency band between 1 and $10mathrmGHz$.
arXiv Detail & Related papers (2019-09-17T19:10:49Z)

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