Tunable-cavity QED with phase qubits

2014/07/14 by J. D. Whittaker, Jed D. Whittaker, F. C. S. da Silva +13 · 32 citations
Computer Science · Physics and Astronomy · #Cavity quantum electrodynamics #Charge qubit #Coupling (piping) #Dephasing #Flux qubit #Materials science #Microwave #Microwave cavity #Phase qubit #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum error correction #Quantum mechanics #Quantum optics and atomic interactions #Qubit #Transmon #Trapped ion quantum computer #quant-ph

paper · pdf · doi:10.1103/physrevb.90.024513

published in Physical Review B 90(2) (American Physical Society) · 17 pages, 10 figures

openalex publication_date 2014/07/14 · arxiv created 2014/08/08 · arxiv updated 2014/08/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We describe a tunable-cavity quantum electrodynamics (QED) architecture with an rf SQUID phase qubit inductively coupled to a single-mode, resonant cavity with a tunable frequency that allows for both microwave readout of tunneling and dispersive measurements of the qubit. Dispersive measurement is well characterized by a three-level model, strongly dependent on qubit anharmonicity, qubit-cavity coupling, and detuning. A tunable-cavity frequency provides a way to strongly vary both the qubit-cavity detuning and coupling strength, which can reduce Purcell losses, cavity-induced dephasing of the qubit, and residual bus coupling for a system with multiple qubits. With our qubit-cavity system, we show that dynamic control over the cavity frequency enables one to avoid Purcell losses during coherent qubit evolutions and optimize state readout during qubit measurements. The maximum qubit decay time T₁=1.5\phantom\rule0.222222em0ex\ensuremathμs is found to be limited by surface dielectric losses from a design geometry similar to planar transmon qubits.

Citations

• Tunable Coupling in Circuit Quantum Electrodynamics Using a Superconducting Charge Qubit with aV-Shaped Energy Level Diagram
• Charge insensitive qubit design derived from the Cooper pair box
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• Direct Wigner Tomography of a Superconducting Anharmonic Oscillator
• Coupling superconducting qubits via a cavity bus
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• Dephasing of a Superconducting Qubit Induced by Photon Noise
• Quantum Simulators