High fidelity quantum state transfer in electromechanical systems with intermediate coupling

Abstract

Hybrid quantum systems usually consist of two or more subsystems, which may take the advantages of the different systems. Recently, the hybrid system consisting of circuit electromechanical subsystems have attracted great attention due to its advanced fabrication and scalable integrated photonic circuit techniques. Here, we propose a scheme for high fidelity quantum state transfer between a superconducting qubit and a nitrogen-vacancy center in diamond, which are coupled to a superconducting transmission-line resonator with coupling strength g1 and a nanomechanical resonator with coupling strength g2, respectively. Meanwhile, the two resonators are parametrically coupled with coupling strength J. The system dynamics, including the decoherence effects, is numerical investigated. It is found that both the small () and large () coupling regimes of this hybrid system can not support high fidelity quantum state transfer before significant technique advances. However, in the intermediate coupling regime (J ~ g1 ~ g2), in contrast to a conventional wisdom, high fidelity quantum information transfer can be implemented, providing a promising route towards high fidelity quantum state transfer in similar coupled resonators systems.

Coupling a single nitrogen-vacancy center with a superconducting qubit via the electro-optic effect

“…With the above considerations we can simulate the system using the following Lindblad master equation [58]: for microwave photons in the frequency range of GHz can be negligible at a temperature around 10 mK. We focus on evaluating the performance of our scheme in the intermediate coupling regime (G i ∼ g 1 = g 2 = g), which we find is the best regime for quantum state transfer, as shown in an electromechanical coupling system [37]. The transfer fidelity can be reduced as the electrooptical coupling strength deviates from the optimal case.…”

“…It indicates that the system can be reliable for high fidelity quantum information transfer. Moreover, conclusions from similar systems consisting of coupled resonators with the same form of the interaction Hamiltonian can be applied to our scheme [37].…”

Robust quantum storage and retrieval in a hybrid system by controllable Stark-chirped rapid adiabatic passages

“…The Hermitian Lamb shift term in the above Eq. (14) can be expressed as H ls (t) = k nm L † nm,k L nm,k S k (ω nm (t)) , where γ k (ω) and S k (ω) are the real part and imaginary part of the bath spectral-density matrix, respectively. For simplicity, the terms associated with Lamb shift H ls can be neglected [44].…”

“…Such memory is one of the basic building blocks for the future large-scale quantum information processing tasks, including scalable quantum computation and long-distance quantum communication. For this purpose, a lot of efforts have been made to combine the advantages of different kinds of quantum systems for building hybrid quantum devices [4][5][6][7], including using ultracold atomic ensembles [8,9], nitrogen-vacancy center ensemble [10][11][12][13][14], and spin ensembles [15,16] coupled with superconducting qubit by transmission line. In the hybrid systems, solid-state elements [1,2] are suitable for engineering the processors, and microscopic systems with long coherence times can be proposed as possible quantum memories.…”

One-step resonant controlled-phase gate on distant transmon qutrits in different 1D superconducting resonators

“…Cavity quantum electrodynamics (QED) 10 provides a promising platform to realize the nonlinear interaction between an atom and a field, and it can achieve indirect nonlinear interaction among atoms or fields. To simulate cavity QED, atom 11 12 13 , spin 14 15 16 17 18 19 20 21 22 23 24 25 , or superconducting qubits 26 27 28 29 30 31 32 33 34 35 36 coupled to optical cavities 37 38 39 40 41 , superconducting resonators 42 43 44 45 , or nanomechanical resonators 46 47 have been studied a lot for quantum information processing both in experiment and in theory 48 .…”