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Related papers: Experimentally Realizable C-NOT Gate in a Flux Qub…

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Charge qubits formed in double quantum dots represent quintessential two-level systems that enjoy both ease of control and efficient readout. Unfortunately, charge noise can cause rapid decoherence, with typical single-qubit gate fidelities…

Mesoscale and Nanoscale Physics · Physics 2019-03-11 Yuan-Chi Yang , S. N. Coppersmith , Mark Friesen

We establish theoretical bounds on qubit detuning for high fidelity controlled-NOT logic gate implementations with weakly coupled Josephson phase qubits. It is found that the value of qubit detuning during the entangling pulses must not…

Quantum Physics · Physics 2015-05-13 Andrei Galiautdinov

Compared to traditional semiconductor control electronics (TSCE) located at room temperature, cryogenic single flux quantum (SFQ) electronics can provide qubit measurement and control alternatives that address critical issues related to…

Recent experiments have demonstrated superconducting transmon qubits with semiconductor nanowire Josephson junctions. These hybrid gatemon qubits utilize field effect tunability characteristic for semiconductors to allow complete qubit…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 L. Casparis , T. W. Larsen , M. S. Olsen , F. Kuemmeth , P. Krogstrup , J. Nygård , K. D. Petersson , C. M. Marcus

High-fidelity two-qubit gates in quantum computers are often hampered by fluctuating experimental parameters. The effects of time-varying parameter fluctuations lead to coherent noise on the qubits, which can be suppressed by designing…

Quantum Physics · Physics 2023-01-06 Mingyu Kang , Ye Wang , Chao Fang , Bichen Zhang , Omid Khosravani , Jungsang Kim , Kenneth R. Brown

We demonstrate new experimental procedures for measuring small errors in a superconducting quantum bit (qubit). By carefully separating out gate and measurement errors, we construct a complete error budget and demonstrate single qubit gate…

With superconducting transmon qubits --- a promising platform for quantum information processing --- two-qubit gates can be performed using AC signals to modulate a tunable transmon's frequency via magnetic flux through its SQUID loop.…

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 consider procedures to realize an approximate universal NOT gate in terms of average fidelity and fidelity deviation. The average fidelity indicates the optimality of operation on average, while the fidelity deviation does the…

Quantum Physics · Physics 2012-12-24 Jeongho Bang , Seung-Woo Lee , Hyunseok Jeong , Jinhyoung Lee

The unit of quantum information is the qubit, a vector in a two-dimensional Hilbert space. On the other hand, quantum hardware often operates in two-dimensional subspaces of vector spaces of higher dimensionality. The presence of higher…

Condensed Matter · Physics 2009-10-31 Rosario Fazio , G. Massimo Palma , Jens Siewert

High-fidelity quantum gate operations are essential for achieving scalable quantum circuits. In spin qubit quantum computing systems, metallic gates and antennas which are necessary for qubit operation, initialization, and readout, also…

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…

The scaleup of quantum computers operating in the microwave domain requires advanced control electronics, and the use of integrated components that operate at the temperature of the quantum devices is potentially beneficial. However, such…

Superconducting transmon qubits comprise one of the most promising platforms for quantum information processing due to their long coherence times and to their scalability into larger qubit networks. However, their weakly anharmonic spectrum…

Mesoscale and Nanoscale Physics · Physics 2017-08-02 Xiu-Hao Deng , Edwin Barnes , Sophia E. Economou

Two-qubit interactions are at the heart of quantum information processing. For single-spin qubits in semiconductor quantum dots, the exchange gate has always been considered the natural two-qubit gate. The recent integration of magnetic…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 T. Meunier , V. E. Calado , L. M. K. Vandersypen

High-fidelity two-qubit gates are essential for scalable quantum computing. We present a scheme based on superconducting transmon qubits and a control pulse delivery protocol that enables arbitrary controlled-phase gates modulated solely by…

High-fidelity two-qubit gates have been demonstrated in systems of two fluxonium qubits; however, the realization of scalable quantum processors requires maintaining low error rates in substantially larger architectures. In this work, we…

We examine how dissipation and gate timing errors affect the fidelity of a sequence of SWAP gates on a chain of interacting qubits in comparison to noise in the interqubit interaction. Although interqubit interaction noise and gate timing…

Mesoscale and Nanoscale Physics · Physics 2022-04-18 Nathan L. Foulk , Robert E. Throckmorton , S. Das Sarma

The superconducting fluxonium circuit is an artificial atom with a strongly anharmonic spectrum: when biased at a half flux quantum, the lowest qubit transition is an order of magnitude smaller in frequency than those to higher levels.…

Recent work (Nathan et al, arXiv:2405.05671) proposed an architecture for a dissipatively stabilized GKP qubit, and protocols for protected Clifford gates. Here we propose a protocol for a protected non-Clifford $\sqrt{T}$ gate at the…

Quantum Physics · Physics 2025-07-29 Liam O'Brien , Gil Refael , Frederik Nathan