Scalable superconducting qubit circuits using dressed states

Abstract

We study a coupling/decoupling method between a superconducting qubit and a data bus that uses a controllable time-dependent electromagnetic field (TDEF). As in recent experiments, the data bus can be either an LC circuit or a cavity field. When the qubit and the data bus are initially fabricated, their detuning should be made far larger than their coupling constant, so these can be treated as two independent subsystems. However, if a TDEF is applied to the qubit, then a "dressed qubit" (i.e., qubit plus the electromagnetic field) can be formed. By choosing appropriate parameters for the TDEF, the dressed qubit can be coupled to the data bus and, thus, the qubit and the data bus can exchange information with the assistance of the TDEF. This mechanism allows the scalability of the circuit to many qubits. With the help of the TDEF, any two qubits can be selectively coupled to (and decoupled from) a common data bus. Therefore, quantum information can be transferred from one qubit to another.

10 pages, 5 figures

References in corpus (9)

• Superconducting Circuits and Quantum Information
• Spectroscopy on two coupled flux qubits
• Parametric coupling for superconducting qubits
• Tunable coupling scheme for flux qubits at the optimal point
• Four-qubit device with mixed couplings
• Low frequency Rabi spectroscopy for a dissipative two-level system
• Hamiltonian for coupled flux qubits
• Direct measurement of the quantum state of the electromagnetic field in a superconducting transmission line
• Quantum manipulation and simulation using Josephson junction arrays

Cited by in corpus (9)

• Quantum information processing with circuit quantum electrodynamics
• Coherence times of dressed states of a superconducting qubit under extreme driving
• Simple unconventional geometric scenario of one-way quantum computation with superconducting qubits inside a cavity
• Dissipation in circuit quantum electrodynamics: lasing and cooling of a low-frequency oscillator
• Protecting entanglement in superconducting qubits
• Controlling entanglement sudden death in cavity QED by classical driving fields
• Variable-frequency-controlled coupling in charge qubit circuits: Effects of microwave field on qubit-state readout
• Time-Resolved Measurement of a Charge Qubit
• Optimal effective current operator for flux qubit accounting for inductive effects