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Related papers: Active Leakage Cancellation in Single Qubit Gates

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The \textit{heavy-fluxonium} circuit is a promising building block for superconducting quantum processors due to its long relaxation and dephasing time at the half-flux frustration point. However, the suppressed charge matrix elements and…

We report a substantially simplified procedure, based on group-theoretic reasoning, for the reduction of qubit leakage in exchange-only spin qubits. We to find exchange sequences which accomplish leakage reduction with only two additional…

Quantum Physics · Physics 2020-12-23 Veit Langrock , David P. DiVincenzo

Leakage is a particularly damaging error that occurs when a qubit leaves the defined computational subspace. Leakage errors limit the effectiveness of quantum error correcting codes by spreading additional errors to other qubits and…

Quantum Physics · Physics 2020-03-13 Natalie C. Brown , Andrew W. Cross , Kenneth R. Brown

We present a general framework for the quantification and characterization of leakage errors that result when a quantum system is encoded in the subspace of a larger system. To do this we introduce new metrics for quantifying the coherent…

Quantum Physics · Physics 2018-03-14 Christopher J. Wood , Jay M. Gambetta

Coherent gate errors are a concern in many proposed quantum computing architectures. These errors can be effectively handled through composite pulse sequences for single-qubit gates, however, such techniques are less feasible for entangling…

Achieving very fast gates that undercut the natural limits set by decoherence requires going into the strong driving limit. Realizing single-qubit control predicted beyond semi-classical, time-dependent modeling has yet to be experimentally…

Near-term quantum computers are primarily limited by errors in quantum operations (or gates) between two quantum bits (or qubits). A physical machine typically provides a set of basis gates that include primitive 2-qubit (2Q) and 1-qubit…

Readout of superconducting qubits faces a trade-off between measurement speed and unwanted back-action on the qubit caused by the readout drive, such as $T_1$ degradation and leakage out of the computational subspace. The readout is…

Quantum Physics · Physics 2025-07-08 S. Hazra , W. Dai , T. Connolly , P. D. Kurilovich , Z. Wang , L. Frunzio , M. H. Devoret

The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to ensure the success of QEC, a protocol capable of…

We analyse a simple exchange-based two-qubit gate for singlet-triplet qubits in gate-defined semiconductor quantum dots that can be implemented in a single exchange pulse. Excitations from the logical subspace are suppressed by a magnetic…

Mesoscale and Nanoscale Physics · Physics 2014-07-30 Matthew P. Wardrop , Andrew C. Doherty

All-microwave control of fixed-frequency superconducting quantum systems offers the potential to reduce control circuit complexity and increase system coherence. Nevertheless, due to the limited control flexibility in qubit parameters, one…

Quantum Physics · Physics 2024-10-11 Ling Jiang , Peng Xu , Shengjun Wu , Jian-An Sun , Fu-Quan Dou

This paper critically examines the leakage current reduction techniques for improving the performance of poly-Si TFTs used in active matrix liquid crystal displays. This is a first comprehensive study in literature on this topic. The review…

Mesoscale and Nanoscale Physics · Physics 2010-08-17 Ali A. Orouji , M. Jagadesh Kumar

A fundamental challenge in quantum computing is to increase the number of operations within the qubit coherence time. While this can be achieved by decreasing the gate duration, the use of shorter signals increases their bandwidth and can…

Quantum Physics · Physics 2025-08-06 İlker Polat , Ramon W. J. Overwater , Maximilian Rimbach-Russ , Fabio Sebastiano

Leakage to non-computational states is a source of correlated errors in both time and space that limits the effectiveness of quantum error correction (QEC) with superconducting circuits. We present and experimentally demonstrate a…

We demonstrate a new technique that adapts single-qubit randomized benchmarking to two-qubit M{\o}lmer-S{\o}rensen gates. We use the controllable gate phase to generate Cliffords that act on a two-state subspace, enabling benchmarking of…

Quantum Physics · Physics 2025-10-13 R. T. Sutherland , A. C. Hughes , J. P. Marceaux , H. M. Knaack , C. M. Löschnauer , R. Srinivas

Quantum computation will rely on quantum error correction to counteract decoherence. Successfully implementing an error correction protocol requires the fidelity of qubit operations to be well-above error correction thresholds. In…

We provide a rigorous analysis of fault-tolerant quantum computation in the presence of local leakage faults. We show that one can systematically deal with leakage by using appropriate leakage-reduction units such as quantum teleportation.…

Quantum Physics · Physics 2007-05-23 Panos Aliferis , Barbara M. Terhal

Non-Abelian geometric phases acquired in cyclic quantum evolution can be utilized as natural resources for constructing robust holonomic gates for quantum information processing. Recently, an extensible holonomic quantum computation (HQC)…

Quantum Physics · Physics 2020-09-09 Bao-Jie Liu , Man-Hong Yung

Users of quantum computers must be able to confirm they are indeed functioning as intended, even when the devices are remotely accessed. In particular, if the Hilbert space dimension of the components are not as advertised -- for instance…

Quantum Physics · Physics 2019-03-22 Armands Strikis , Animesh Datta , George C. Knee

Superconducting qubits are a promising platform for building fault-tolerant quantum computers, with recent achievement showing the suppression of logical error with increasing code size. However, leakage into non-computational states, a…