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Related papers: Cat-qubit-inspired gate on cos($2\theta$) qubits

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Addressability of spin qubits in a silicon double quantum dot setup in the (1,1) charge configuration relies on having a large difference between the Zeeman splittings of the electrons. When the difference is not sufficiently large, the…

Mesoscale and Nanoscale Physics · Physics 2020-04-08 Utkan Güngördü , J. P. Kestner

Kerr parametric oscillators (KPOs), two-photon driven Kerr-nonlinear resonators, can stably hold coherent states with opposite-sign amplitudes and are promising devices for quantum computing. Recently, we have theoretically proposed a…

Quantum Physics · Physics 2025-02-04 Hiroomi Chono , Hayato Goto

Across leading qubit platforms, a common trade-off persists: increasing coherence comes at the cost of operational speed, reflecting the notion that protecting a qubit from its noisy surroundings also limits control over it. This…

We present a native three-qubit entangling gate that exploits engineered interactions to realize control-control-target and control-target-target operations in a single coherent step. Unlike conventional decompositions into multiple…

Quantum Physics · Physics 2025-08-15 Xuexin Xu , Siyu Wang , Radhika Joshi , Rihan Hai , Mohammad H. Ansari

A high degree of controllability and long coherence time make the nuclear spin of a phosphorus donor in isotopically purified silicon a promising candidate for a quantum bit. However, long-distance two-qubit coupling and fast, robust gates…

Quantum Physics · Physics 2020-05-22 James Simon , F. A. Calderon-Vargas , Edwin Barnes , Sophia E. Economou

Capacitively coupled semiconductor spin qubits hold promise as the building blocks of a scalable quantum computing architecture with long-range coupling between distant qubits. However, the two-qubit gate fidelities achieved in experiments…

Mesoscale and Nanoscale Physics · Physics 2015-10-29 Xin Wang , Edwin Barnes , S. Das Sarma

Intrinsically protected superconducting qubits are a promising route toward enhancing coherence times and advancing hardware towards applications in quantum computing. The $\cos(2\varphi)$ qubit achieves protection against qubit relaxation…

Coherence of superconducting qubits can be improved by implementing designs that protect the parity of Cooper pairs on superconducting islands. Here, we introduce a parity-protected qubit based on voltage-controlled semiconductor nanowire…

Superconducting protected qubits aim to achieve sufficiently low error rates so as to allow realization of error-corrected, utility-scale quantum computers. A recent proposal encodes a protected qubit in the quasicharge degree of freedom of…

Quantum Physics · Physics 2026-01-09 Nicholas M. Christopher , Deniz E. Stiegemann , Abhijeet Alase , Thomas M. Stace

Using geometric phases to realize noise-resilient quantum computing is an important method to enhance the control fidelity. In this work, we experimentally realize a universal nonadiabatic geometric quantum gate set in a superconducting…

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

Spin qubits in quantum dots define an attractive platform for scalable quantum information because of their compatibility with semiconductor manufacturing, their long coherence times, and the ability to operate at temperatures exceeding one…

Mesoscale and Nanoscale Physics · Physics 2020-07-20 L. Petit , M. Russ , H. G. J. Eenink , W. I. L. Lawrie , J. S. Clarke , L. M. K. Vandersypen , M. Veldhorst

We propose a setup for universal and electrically controlled quantum information processing with hole spins in Ge/Si core/shell nanowire quantum dots (NW QDs). Single-qubit gates can be driven through electric-dipole-induced spin resonance,…

Mesoscale and Nanoscale Physics · Physics 2013-12-17 Christoph Kloeffel , Mircea Trif , Peter Stano , Daniel Loss

We present a way for implementing an n-qubit controlled-rotation gate with three-level superconducting qubit systems in cavity QED. The two logical states of a qubit are represented by the two lowest levels of each system while a…

Quantum Physics · Physics 2015-05-28 Chui-Ping Yang

The Kerr-cat qubit is a bosonic qubit in which multi-photon Schrodinger cat states are stabilized by applying a two-photon drive to an oscillator with a Kerr nonlinearity. The suppressed bit-flip rate with increasing cat size makes this…

Gatemon qubits are the electrically tunable cousins of superconducting transmon qubits. In this work, we demonstrate the full coherent control of a gatemon qubit based on hole carriers in a Ge/Si core/shell nanowire, with the longest…

Resonant exchange qubits are a promising addition to the family of experimentally implemented encodings of single qubits using semiconductor quantum dots. We have shown previously that it ought to be straightforward to perform a CPHASE gate…

Mesoscale and Nanoscale Physics · Physics 2016-03-02 Matthew P. Wardrop , Andrew C. Doherty

We propose to increase the fidelity of two-qubit resonator-induced phase gates in circuit QED by the use of narrowband single-mode squeezed drive. We show that there exists an optimal squeezing angle and strength that erases qubit…

Quantum Physics · Physics 2016-05-11 Shruti Puri , Alexandre Blais

We propose a scheme for a two-qubit conditional phase gate by quantum Zeno effect with semiconductor quantum dots. The system consists of two charged dots and one ancillary dot that can perform Rabi oscillations under a resonant laser…

Other Condensed Matter · Physics 2008-10-27 K. J. Xu , Y. P. Huang , M. G. Moore , C. Piermarocchi

Fast, high-fidelity single and two-qubit gates are essential to building a viable quantum information processor, but achieving both in the same system has proved challenging for spin qubits. We propose and analyze an approach to perform a…

Quantum Physics · Physics 2018-06-13 S. P. Harvey , C. G. L. Bøttcher , L. A. Orona , S. D. Bartlett , A. C. Doherty , A. Yacoby