We propose the schemes of quantum secure direct communication (QSDC) based on secret transmitting order particles. In these protocols, particles ensures security communication, and no messages are leaked even if is interrupted for security. This strategy also generalized to dialogue. It not only unconditional but improves efficiency communication.

Unlike the Rydberg blockade regime, antiblockade regime (RABR) allows more than one atom to be excited, which can bring other interesting phenomena and applications. We propose an alternative scheme quickly achieve RABR. The proposed RABR implemented by adjusting detuning of classical driving field, is, in turn, based on former numbers excited atoms. In contrast schemes, current enables two atoms states a short period time thus is useful for large-scale quantum information processing. used...

We propose several schemes for implementing a two-qubit quantum phase gate between two Rydberg atoms. The could be realized in one step without adiabatic passage which depends on the specifical shapes and tailored pulse sequences of laser fields. When Rydberg-Rydberg-interaction (RRI) strength parameters driving fields satisfy some certain conditions, effective Rabi oscillation two-excitation state ground would generated, is out blockade regime essential our scheme. In addition, individual...

Although the three-body Rydberg antiblockade regime (RABR) can produce Rabi oscillation between collective excited state and ground state, it is still hard to use RABR construct three-qubit quantum logic gate in one step since effective Hamiltonian always accompanied by undesired Stark shifts. In order overcome this difficulty, an additional laser introduced eliminate shifts ground-state subspace. And initial condition modified remaining collective-excitation The then generalized $n...

We propose a scheme to generate squeezed states of magnon and phonon modes verify squeezing transfer between different distinct frequencies in cavity magnomechanical system which is composed microwave yttrium iron garnet sphere. present that by activating the magnetostrictive force ferrimagnet, realized driving mode with red-detuned blue-detuned fields, driven can be prepared state. Moreover, transferred via cavity-magnon beamsplitter interaction strong coupling. show under weak coupling...

We propose a simple scheme to generate quantum entanglement and one-way steering between distinct mode pairs in generic cavity magnomechanical system, which is composed of microwave yttrium iron garnet sphere supporting magnon phonon modes. The pumped by weak squeezed vacuum field, plays an important role for establishing steering. It found that when the driven red-detuned laser, maximum phonon-to-photon can be effectively generated via adjusting ratio two coupling rates. While under much...

Magnon blockade is an effective physical mechanism to generate a single magnon, which of great importance in quantum information processing. We present scheme realize the unconventional magnon effect by using Kerr nonlinearity cavity electromagnonic system. Under weak driving conditions, we give optimal parameter conditions for antibunching through analytical calculations, are good agreement with numerical results. Furthermore, find that necessary create blockade. In particular, can be...

We propose to achieve and enhance the magnon blockade effect in an optomechanical-magnetic system based on a quantum destructive interference mechanism between three indirect transition pathways. By introducing degenerate parametric amplifier, we analytically obtain optimal gain phase for achieving blockade. Under optimized parameter conditions, driving detunings of cavity modes can be flexibly controlled smallest second-order correlation function. Moreover, exhibit fascinating features by...

In this paper a quantum dialogue scheme is proposed by using N batches of single photons. The same secret message encoded on each batch photons the sender with two different unitary operations, and then are sent to receiver. After eavesdropping check, one remaining It shown that intercept-and-resend attack coupling auxiliary modes can be resisted more efficiently, because only once in our scheme.

We propose a simplified parity meter for photonic qubits with cross-Kerr nonlinearities, homodyne measurement, and some optical elements. Our scheme has lower error probability than the protocol proposed in Nemoto Munro [Phys. Rev. Lett. 93, 250502 (2004)]. Based on present meter, we achieve cluster-state preparation, complete Bell-state analyzer, quantum teleportation. All of these schemes are nearly deterministic regime little noise include less elements, which makes our more meaningful...

Using linear optical manipulation, single photons, entangled photon pairs, measurement, and classical communication, we propose a scheme for two-spin-qubit phase gate the teleportation of controlled-not between two electron spins from acting on local qubits to remote using quantum dots in microcavities. The is based spin selective reflection cavity achieved deterministic way by sequential detection photons single-qubit rotations self-assembled GaAs-InAs dot. feasibility assessed showing that...

Through analyzing the effective dynamics of two Rydberg atoms under dispersive coupling process, we give a method to modify traditional antiblockade regime with simultaneous driving without adding any extra controls and resources. The modified can be used construct controlled-PHASE controlled-NOT gates in one step manipulating shape amplitude, tailoring sequences pulses. For gate, only pumping process from ground state each atom is required thus resource minimal. And atomic addressability...

We study the effects of parity-time(PT)-symmetry on photon blockade and distinguish different mechanisms in a double-cavity optomechanical system. By studying light statistics system, we find completely behaviors when PT-symmetry is broken or unbroken, which related to PT phase transition. Furthermore, an interesting phenomenon that two cavities are blocked at same time found with appropriate system parameters. Those statistical phenomenons all analyzed detail demonstrated by analytically...

We propose an alternative scheme of shortcuts to a quantum controlled phase gate in much shorter time based on the approach Lewis-Riesenfeld invariants cavity electrodynamics systems. This can be used perform one-qubit gate, two-qubit as well multiqubit gate. The strict numerical simulations demonstrate that total operation for implementing gates is than previous schemes and very robust against decoherence.

A scheme is proposed to cool a rotating mirror close its ground state in double-Laguerre-Gaussian-cavity optomechanical system, where an auxiliary cavity and two-level atomic ensemble simultaneously couple the original cavity. By choosing parameters reasonably, we find that cooling process of can be strengthened greatly while heating suppressed effectively. We show ground-state work well no matter whether weak or strong coupling regime for Compared with previous related schemes, our works...

Abstract The magnon blockade effect in a parity‐time () symmetric‐like three‐mode cavity magnomechanical system involving the magnon–photon and magnon–phonon interactions is investigated. In broken unbroken ‐symmetric regions, second‐order correlation function calculated analytically numerically, respectively, optimal value of detuning further determined. By adjusting different parameters, mechanisms are studied it found that perfect can be observed under weak parameter mechanism. This work...

Abstract Photon blockade is an effective way to generate single photon, which of great significance in quantum state preparation and information processing. Here we investigate the statistical properties photons a double-cavity optomechanical system with nonreciprocal coupling, explore photon weak strong coupling regions respectively. To achieve blockade, give optimal parameter relations under different mechanisms. Moreover, find that blockades their respective mechanisms exhibit completely...

We extend the recent result of a bipartite Bell singlet [A. W. Carr and M. Saffman, Phys. Rev. Lett. 111, 033607 (2013)] to stationary three-dimensional entanglement between two-individual neutral Rydberg atoms. This proposal makes full use coherent dynamics provided by Rydberg-mediated interaction dissipative factor originating from spontaneous emission state. The numerical simulation master equation reveals that both target state negativity $\mathcal{N}({\stackrel{\ifmmode \hat{}\else...

We provide a family of counterexamples to first formulation the dynamical Manin–Mumford conjecture. propose revision this conjecture and prove it for arbitrary subvarieties Abelian varieties under action group endomorphisms lines diagonal ⁠.

In the usual optomechanical cooling, even if system has no thermal component, it still a quantum limit---known as backaction limit (QBL)---on minimum phonon number related to shot noise. By studying side-band cooling regime in systems (OMSs), we find that can be improved significantly when frequency modulation (FM) suppress Stokes heating processes is introduced into system. We analyze and demonstrate reasons of below QBL redefined whole stable region standard OMSs. The above analyses are...

Abstract We propose a scheme for the creation of robust entanglement between movable mirror and atomic ensemble at macroscopic level in coupled optomechanical system. numerically simulate degree bipartite show that it depends on coupling strength cavities is with respect to certain environment temperature. Inspiringly surprisingly, according reported relation mechanical damping rate frequency mirror, numerical simulation result shows such persists temperature up 170 K, which breaks liquid...

We propose a scheme to achieve controllable unidirectional reflectionless propagation at exceptional point (EP) in non-ideal parity-time metasurface consisting of two silver ring resonators. The can be manipulated by simply adjusting the angle incident wave and distance s between rings based on far field coupling. In addition, wide range ∼25° is available propagation. Moreover, EP insensitive polarization due two-ring structure.