Universal Gate for Fixed-Frequency Qubits via a Tunable Bus

By David C. McKay, Stefan Filipp, Antonio Mezzacapo, Easwar Magesan, Jerry M. Chow, Jay M. Gambetta. 2016

274 citations recorded by the source corpus.

The authors address a critical scalability issue in quantum computer design by activating a resonant exchange interaction. They achieve this by coupling two fixed-frequency superconducting qubits with a bus that is modulated at the frequency difference between the qubits. This yields a high-fidelity iSWAP entangling gate, which is sought as an important component for fault-tolerant quantum circuits in the surface-code architecture. The general nature of the interaction also suggests applications in quantum simulation, annealing, and bath engineering.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/e3e303b0ee82b9fed50465cd524c5883a984fdba

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In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Efficient Z gates for quantum computing (2016, background): “Similar errors are common when driving two-qubit gates, such as the parametric iSWAP [10], cross-resonance [11] and adiabatic CZ [12], so VZ-gates plus pulse shaping is also applicable in multiqubit systems.”
Leakage reduction in fast superconducting qubit gates via optimal control (2020, methodology): “[42] McKay, D.”
Demonstration of quantum volume 64 on a superconducting quantum computing system (2020, background): “The Phase gate can be achieved with zero time and error [22].”
Tunable Coupling Scheme for Implementing High-Fidelity Two-Qubit Gates (2018, background): “However, we emphasize that other types of two-qubit gates, such as a controlled-phase (C-phase) gate [38] or a parametrically driven gate [34], are also compatible with our scheme.”
Quantum information processing with superconducting circuits: a review (2016, methodology): “In the resonator induced phase gate (RIP) scheme [141, 221, 265] fixed frequency transmons are statically coupled to the same bus resonator driven at the difference frequency of two qubits.”
Parametrically Activated Entangling Gates Using Transmon Qubits (2017, background): “many resonator modes [26], two transmon qubits coupled by a tunable mediating qubit [16, 25], or two tunable transmons coupled to a mediating resonator [23, 24].”
On-demand directional microwave photon emission using waveguide quantum electrodynamics (2022, methodology): “Next, the frequency of the tunable coupler C34 is modulated at the detuning of this qubit pair to implement an entangling √ iSWAP gate [61].”