Efficient spin Bell states and Greenberger–Horne–Zeilinger states analysis in the quantum dot–microcavity coupled system

Abstract

motivated an intensive research in the generation and the manipulation of entangled states.Typical two particles bipartite entangled states are Bell states [19], and they can be used in a large quantity of quantum communication schemes. So, the complete and determinate analysis of the Bell states is a crucial step in QIP. On the other hand, multiparticle systems also attract more and more attentions of researchers, referred to as Greenberger-Horne-Zeilinger (GHZ) states [20], W states [21], and cluster states [22], etc. Especially, the GHZ states [20], which can provide possibilities to test quantum mechanics against local hidden theory without inequality [19], is one of the most important resource in QIP. Till now, due to the large information capacity, great interest has arisen regarding the significant role of GHZ states in the foundations of quantum mechanics measurement theory and quantum communication [23][24][25][26][27][28][29]. Contrary to bipartite entangled states, GHZ states exhibit a special kind of entanglement between N ≥ 3 parties, providing a possibility to test quantum nonlocality in a one-shot manner. So, of common interest is the problem of how to realize the GHZ states analysis using current technologies.We all know that an analyzer that can completely and determinately distinguish all of the Bell states and the GHZ states without destroying quantum qubits is a very powerful tool. Thus, lots of Bell states and GreenbergerHorne-Zeilinger states analysis schemes [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] have been proposed for different systems with several methods. For example, Walborn et al. [36] have proposed a simple scheme for complete Bell states measurement of photons using hyperentangled states. Houwelingen et al. [41] have proposed a scheme, which can distinguish two of the eight maximally entangled polarized photon GHZ states. Sheng et al. have proposed a Bell state analysis scheme [45] with quantum nondemolition detectorsAbstract We propose a scheme for spin Bell states and GHZ states analysis with quantum dots inside double-sided optical microcavities. The proposed setup involves simple linear optical elements, single polarized photon, and the conventional photon detectors that only distinguish the vacuum and nonvacuum Fock number states. This makes the protocol more realizable in experiments. Numerical simulation shows that the high fidelities can be realized when the side leakage and cavity loss are low, which is feasible in the weak-coupling regime. With all the advantages above, our scheme could be useful in quantum communication processing.

Hyperparallel transistor, router and dynamic random access memory with unity fidelities

“…Currently, photon-mediated (such as cross-Kerr [42][43][44], neutral atoms [45][46][47][48], atom ensembles [29,49], and artificial atoms [50][51][52][53][54][55]) interactions are often employed to overcome the intrinsic weak interactions between individual photons charter of parallel and hyperparallel photonic quantum computing. In recent years, artificial atoms (quantum dot in semiconductors [50][51][52][53], nitrogen vacancy defect centre in diamond [54], superconductor [55]) have been received growing interest due to their relatively long coherence time [56,57], sensitive and quick manipulation, high-fidelity readout [58][59][60], custom-designed features [61,62], as well as much large linewidths. Quantum dots (QDs) provide a better matter qubit system [63,64] because they could be designed to have certain characteristics and be assembled in large arrays.…”

Complete and Nondestructive Atomic Greenberger–Horne–Zeilinger‐State Analysis Assisted by Invariant‐Based Inverse Engineering

“…Among different entangled states, maximally entangled states like Bell states and Greenberger–Horne–Zeilinger (GHZ) states have attracted much attention of researchers and have been studied adequately, which unavoidably caused the problems about the analysis of Bell states or GHZ states. Up to now, complete and nondestructive analysis of Bell states has been realized by various means in many previous protocols . For instance, Sheng et al .…”

Complete Bell-state analysis for superconducting-quantum-interference-device qubits with a transitionless tracking algorithm

“…Therefore, to achieve complete and nondestructive Bell-state analysis and to exploit the advantages of other physical systems, researchers have turned their attentions on Bell states in various systems by applying many new techniques, such as nonlinearities and hyperentanglement. Until now, complete and nondestructive Bell-state analysis for photons [22][23][24][25][26][27][28], atoms [29], spins inside quantum dots [30,31] and nitrogenvacancy centers [32] have been reported.…”