Dissipative preparation of steady Greenberger-Horne-Zeilinger states for Rydberg atoms with quantum Zeno dynamics

We propose a resource-efficient error-rejecting entangled-state analyzer for polarization-encoded multiphoton systems. Our analyzer is based on two single-photon quantum-nondemolition detectors, where each of them is implemented with a four-level emitter (e.g., a quantum dot) coupled to a onedimensional system (such as a micropillar cavity or a photonic nanocrystal waveguide). The analyzer works in a passive way and can completely distinguish 2 n Greenberger-Horne-Zeilinger (GHZ) states of n photons without using any active operation or fast switching. The efficiency and fidelity of the GHZ-state analysis can, in principle, be close to unity, when an ideal single-photon scattering condition is fulfilled. For a nonideal scattering, which typically reduces the fidelity of a GHZstate analysis, we introduce a passively error-rejecting circuit to enable a near-perfect fidelity at the expense of a slight decrease of its efficiency. Furthermore, the protocol can be directly used to perform a two-photon Bell-state analysis. This passive, resource-efficient, and error-rejecting protocol can, therefore, be useful for practical quantum networks.

Section: Introductionmentioning

confidence: 99%

Resource-efficient analyzer of Bell and Greenberger-Horne-Zeilinger states of multiphoton systems

Miranowicz

Xia

et al. 2019

“…|5p 1/2 . The effective twophoton Rabi frequency is achieved to be a reasonable value Ω 0 = 2π × 2.5MHz [27], with which the ground state |1 is coupled to the |r by a big detuning ∆ = 2π × 36MHz, giving rise to the characteristic frequency of system ω 0 = Ω 2 0 /4∆ = 0.273MHz. In the real implementation two atoms can be trapped separately with an interatomic distance R c = 9.5µm for realizing a considerable vdWs interaction U rr = 2π × 72MHz, driven by a periodically time-dependent laser beam Ω(t) with amplitude Ω 0 and modulation frequency ω = ω 0 = 0.273MHz.…”

Section: Feasibility and Ways For Further Facilitationmentioning

confidence: 98%

“…Nevertheless this approach simultaneously suffering from the complexity of energy levels and laser fields combining with Rydberg interactions [20][21][22], still has not been realized in experiment. * jqian1982@gmail.com Other alternative approaches are proposed by combining an optical cavity to trigger the entanglement formation, because the cavity decay treating as an auxiliary loss channel towards the target state, can permit a reduced stabilization time that is smaller than tens of microseconds depending on the absolute value of cavity mode coupling [23][24][25][26][27]. More recently an intriguing improvement for a ten-times faster generation of steady entanglement in a cavity is suggested by using pulse modulation, achieving an exponentially enhancement for the atom-cavity coupling [22].…”

Section: Introductionmentioning

confidence: 99%

Periodically driven facilitated high-efficiency dissipative entanglement with Rydberg atoms

et al. 2020

A time-dependent periodical field can be utilized to efficiently modify the Rabi coupling of system, exhibiting nontrivial dynamics. We propose a scheme to show that this feature can be applied for speeding up the formation of dissipative steady entanglement based on Rydberg anti-blockade mechanism in a simplified configuration, fundamentally stemming from a frequency match between the external-field modulation frequency and the systematic characteristic frequency. In the presence of an optimal modulation frequency that is exactly equal to the central frequency of driving field, it enables a sufficient residence time of the two-excitation Rydberg state for an irreversible spontaneous decay onto the target state, leading to an accelerated high-fidelity steady entanglement ∼ 0.98, with a shorter formation time < 400µs. We show that, a global maximal fidelity benefits from a consistence of microwave-field coupling and spontaneous decay strengths, by which the scheme promises a robust insensitivity to the initial population distributions. This simple approach to facilitate the generation of dissipative entangled two-qubit states by using periodic drivings may guide a new experimental direction in Rydberg quantum technology and quantum information.

“…It enables tunable, anisotropic interactions and provides the possibility to study the novel exotic many-body physics [19][20][21][22][23] In addition, the combination of interatomic Rydberg interactions and two-photon detuning leads to an opposite effect, the Rydberg antiblockade, which theoretically predicted by Ates et al [24] and was experimentally observed by Amthor et al [25]. The Rydberg antiblockade can achieve the multiple Rydberg excitations while restrain the Rydberg blockade, and its exploration is of particular interest not only for multiqubit logic gates [26], but also for preparations of quantum entanglement [27][28][29][30][31], e.g. Carr et al analyzed an approach to obtain high fidelity entanglement and antiferromagnetic states by Rydberg antiblockade [27].…”

Section: Introductionmentioning

confidence: 99%

“…Carr et al analyzed an approach to obtain high fidelity entanglement and antiferromagnetic states by Rydberg antiblockade [27]. Quite recently, our group made use of the cooperation between Rydberg antiblockade, quantum Zeno dynamics, and atomic spontaneous emission to prepare the tripartite GHZ state and W state, respectively * Corresponding author: shaoxq644@nenu.edu.cn [30,31]. Moreover, by virtue of the Rydberg-antiblockade effect and the Raman transition, we have devised a mechanism of ground-state blockade to generate the high-fidelity entanglement [32].…”

Section: Introductionmentioning

confidence: 99%

Unconventional Rydberg pumping and applications in quantum information processing

Shao

2018

Self Cite

We propose a mechanism of unconventional Rydberg pumping (URP) via simultaneously driving each Rydberg atom by two classical fields with different strengths of Rabi frequencies. This mechanism differs from the general Rydberg blockade or Rydberg antiblockade since it is closely related to the ground states of atoms, i.e. two atoms in the same ground state are stable while two atoms in different ground states are resonantly excited. Furthermore, we find the URP can be employed to simplify some special quantum information processing tasks, such as implementation of a three-qubit controlled phase gate with only a single Rabi oscillation, preparation of two-and three-dimensional steady-state entanglement with two identical atoms, and realization of the autonomous quantum error correction in a Rydberg-atom-cavity system. The feasibility of the above applications is certified explicitly by the state-of-the-art technology.