Generating entangled states from coherent states in circuit-QED

Abstract

Entangled states are self-evidently important to a wide range of applications in quantum communication and quantum information processing. We propose an efficient and convenient two-step protocol for generating Bell states and NOON states of two microwave resonators from merely coherent states. In particular, we derive an effective Hamiltonian for resonators coupled to a superconducting $\Lambda$-type qutrit in the dispersive regime. By the excitation-number-dependent Stark shifts of the qutrit transition frequencies, we are able to individually control the amplitudes of specified Fock states of the resonators associated with relevant qutrit transition, using carefully tailored microwave drive signals. Thereby an arbitrary bipartite entangled state in Fock space can be generated by a typical evolution-and-measurement procedure. We analysis the undesired state transitions and the robustness of our protocol against the systematic errors from the microwave driving intensity and frequency, the quantum decoherence of all components, and the crosstalk of two resonators. In addition, we demonstrate that our protocol can be extended to a similar scenario with a $\Xi$-type qutrit.

13 pages, 11 figures, 1 table

References in corpus (14)

• Beyond the Jaynes-Cummings model: circuit QED in the ultrastrong coupling regime
• Quantum Optical Metrology -- The Lowdown on High-N00N States
• Magnetic field sensing beyond the standard quantum limit using 10-spin NOON states
• Low-decoherence flux qubit
• Coherence and Decay of Higher Energy Levels of a Superconducting Transmon Qubit
• Deterministic entanglement of photons in two superconducting microwave resonators
• Proposal for generating and detecting multi-qubit GHZ states in circuit QED
• Atomtronic protocol designs for NOON states
• High-Fidelity Entangled Bell States via Shortcuts to Adiabaticity
• Universal controlled-phase gate with cat-state qubits in circuit QED
• Dispersive Coupling Between the Superconducting Transmission Line Resonator and the Double Quantum Dots
• Construction of a qudit using Schrodinger cat states and generation of hybrid entanglement between a discrete-variable qudit and a continuous-variable qudit
• Optimizing measurement-based cooling by reinforcement learning
• Simultaneous cooling by measuring one ancillary system

Cited by in corpus (1)

• Dynamically stable two-mode squeezing in cavity optomechanics