One-way Steering Research Articles

Dissipation-induced nonreciprocal magnon entanglement and one-way steering in waveguide electromagnonics

Dissipation-induced nonreciprocal magnon entanglement and one-way steering in waveguide electromagnonics

Steering, bipartite and genuine tripartite entanglement in five-mode hybrid cavity electro-optomechanical systems

We propose a scheme to generate one-way steering, bipartite and genuine tripartite entanglement in a five-mode hybrid cavity electro-optomechanical system consisted of an optical cavity, a mechanical resonator, and three microwave cavity modes with the help of a squeezed vacuum field. The optical cavity is pumped by a squeezed vacuum field. The mechanical resonator is formed by a freely vibrating silicon nitride membrane which is a part of a capacitor in a inductor-capacitor circuit forming three microwave resonators. We find that there is robust entanglement and one-way steering between the optical cavity mode and microwave cavity modes in the presence of the squeezed vacuum field. Particularly, there is steady-state genuine tripartite entanglement between three microwave cavity modes which is robust against thermal fluctuations. Our scheme could be useful for various quantum tasks based on hybrid electro-optomechanical systems fabricated on chips.

Manipulating one-way quantum steering in a mechanical gain-loss optomechanical system

Based on the phenomenon of exceptional points (EPs) in the optomechanically induced mechanical PT-symmetric binary and ternary systems, we propose a mechanism to generate the perfect one-way quantum steering between two totally symmetric modes, respectively. By investigating the quantum steering behavior in the close vicinity of EP, we find that the optimal one-way quantum steering can be successfully generated at the EP in the PT-symmetric binary mechanical system. When pushing the system towards the EP, we show that not only is the broadest region of the one-way quantum steering achieved, but the robustness against the thermal noise can be significantly enhanced. In addition, the direction of the one-way quantum steering can be precisely controlled only by altering the sign of the detuning of the cavity field. What’s more, we analyze the mean populations of the involved modes to further support our findings and find that the occurrence of the one-way quantum steering depends mainly on the difference in the populations between the two target modes. We also successfully extend our findings to the high-order EP, and the desired one-way quantum steering can still be generated in the PT-symmetric ternary mechanical system when it operates at the EP. Our scheme opens up an alternative manipulation method to explore the various novel quantum effects exploiting the EPs and has significant potential applications in quantum nonreciprocal devices.

Generation of quantum entanglement and Einstein–Podolsky–Rosen steering in a hybrid qubit-cavity optomagnonic system

We propose a scheme to generate quantum entanglement and Einstein–Podolsky–Rosen (EPR) steering in a hybrid qubit-cavity optomagnonic system. This hybrid system consists of a microwave cavity, a yttrium-iron-garnet (YIG) sphere, and a superconducting qubit. Due to the existence of the effective parametric (beamsplitter) coupling between the optical mode and the magnon mode (superconducting qubit), the quantum entanglement and EPR steering between the magnon and qubit modes can be achieved. It is found that bipartite entanglement and one-way quantum steering are limited to a narrow range of parameters, while two-way quantum steering appears in a wide range of parameters. Furthermore, we demonstrate that the entanglement between the magnon and the collective dressed modes, as well as the conversion of one-way quantum steering, can also be achieved. Our scheme may provide a feasible approach to exploring quantum information processing.

Phase-controlled quantum entanglement and one-way steering in cavity magnonic system

Phase-controlled quantum entanglement and one-way steering in cavity magnonic system

Generated genuine tripartite steering and its monogamy in the background of a Kerr-Newman black hole* *Supported by the National Natural Science Foundation of China (12205133, LJKQZ20222315, JYTMS20231051), and the Special Fund for Basic Scientific Research of Provincial Universities in Liaoning (LS2024Q002)

We study the redistribution of quantum steering and its monogamy in the presence of a four-dimensional Kerr-Newman black hole. The gravitational effect of the Kerr-Newman black hole is shown to generate genuine tripartite steering between causally disconnected regions, depending on the polar angle, angular momentum, electric charge, and magnetic charge of the black hole. We obtain strong evidence of steering monogamy, that is, the "sudden death" of the A → B steering results in the "sudden birth" of B → B steering. We also obtain the condition of maximal steering asymmetry, that is, , revealing the transition between two-way and one-way steering in Kerr-Newman spacetime.

Enhancement and manipulation of nonreciprocity via dissipative coupling.

Classical and quantum nonreciprocity have important applications in information processing due to their special one-way controllability for physical systems. In this paper we investigate the nonreciprocal transmission and quantum correlation by introducing the dissipative coupling into a linear coupling system consisting of two microdisk resonators. Our research results demonstrate that even in the case of a stationary resonator, dissipative coupling can effectively induce nonreciprocity within the system. Moreover, the degree of nonreciprocity increases with the dissipative coupling strength. Importantly, the phase shift between the dissipative coupling and coherent coupling serves as a critical factor for controlling both nonreciprocal transmision and one-way quantum steering. Consequently, the introduction of dissipative coupling not only enhances the nonreciprocal transmission and nonreciprocal quantum correlation but also enables on-demand manipulation of nonreciprocity. This highlights dissipation as an effective means for manipulating classical and quantum nonreciprocity, thus playing a favorable role in chiral quantum networks.

Manipulation of tunable nonreciprocal entanglement and one-way steering induced by two-photon driving

Manipulation of tunable nonreciprocal entanglement and one-way steering induced by two-photon driving

Generating stationary entanglement and one-way steering in a hybrid cavity electro-optomechanical system via a squeezed vacuum field

Generating stationary entanglement and one-way steering in a hybrid cavity electro-optomechanical system via a squeezed vacuum field

Quantum synchronization and controllable Einstein-Podolsky-Rosen steering of a dynamical Casimir waveguide system composed of giant atoms

We obtain the quantum synchronization and controllable Einstein-Podolsky-Rosen (EPR) steering through theoretical research in a Dynamical Casimir array (DCA) composed of two giant atoms. We achieve one-way or two-way EPR steering between giant atoms, as well as the reversal and exchange of monogamy relations by adjusting system parameters. Remarkably, we find that the system temperature can serve as a switch for regulating different types of EPR steering. By adjusting this switch, we obtain the sudden death of EPR steering between giant atoms and the resurrection of two-way EPR steering between Casimir photons and giant atoms. Most importantly, the resurrection of EPR steering generated by the temperature shows the synchronicity and shareability of multipartite EPR steering. Contrary to the monogamy relations, the shareability of EPR steering allows the state of one party to be steered by two or more observers. The emergence of quantum synchronization and shareability of EPR steering provides an innovative perspective and approach for studying multipartite EPR steering and has potential applications in many quantum information protocols.

All-optical Einstein-Podolsky-Rosen steering swapping.

Einstein-Podolsky-Rosen (EPR) steering, an important resource in quantum information, describes the ability of one party to influence the state of another party through local measurements. It differs from Bell nonlocality and entanglement due to its asymmetric property. EPR steering swapping allows two spatially independent parties to present EPR steering without direct interaction. Here, we theoretically propose an all-optical EPR steering swapping (AOSS) scheme based on low-noise high-broadband optical parametric amplifiers (OPAs). A low-noise high-broadband OPA is utilized to implement the function of Bell-state measurement without detection, avoiding the optic-electro and electro-optic conversions. After AOSS, one-way and two-way EPR steering between two independent optical modes can be obtained. Our scheme provides a guidance for the construction of a measurement-free, all-optical broadband quantum network utilizing EPR steering swapping.

Dissipative-coupling-induced steady-state entanglement and one-way steering in a cavity-magnonics system

Dissipative-coupling-induced steady-state entanglement and one-way steering in a cavity-magnonics system

Testing the one-way steering with any bipartite entangled state: a numerical simulation with electrons on liquid Helium

Quantum entanglement is one of the basic features of the quantum system, and it can be divided into three kinds: non-steering, one-way steering, and multi-way steering. The multi-way steering is mutual for the bipartite system, i.e., Alice can steer Bob and Bob can also steer Alice. While one-way steering is asymmetrical, it provides various potential applications for quantum information processing. The existence of one-way steering has been experimentally tested with certain specific bipartite entangled states, typically such as the optical Werner states. Here we show that any bipartite entangled state can be experimentally determined to be one-way steering or not by testing the relevant linear steering inequality. By constructing the proper unitary operations, we show that the required joint projective measurement can be performed for the tests. Specifically, we demonstrate the experimental feasibility of the proposal with a typical solid-state experimental platform, i.e., electrons trapped on liquid Helium, by applying the electron trap and microwave driving techniques.

Gaussian quantum steering in multi-event horizon spacetime

We study Gaussian quantum steering in the Schwarzschild–de Sitter (SdS) spacetime that is endowed with both a black hole event horizon (BEH) and a cosmological event horizon (CEH), giving rise to two different Hawking temperatures. It is shown that the Hawking effect of the black hole always reduces the quantum steering, but the Hawking effect of the expanding universe does not always play the same role. For the first time, we find that the Hawking effect can improve quantum steering. We also find that the observer who locates in the BEH has stronger steerability than the observer who locates in CEH. Further, we study the steering asymmetry, and the conditions for two-way, one-way and no-way steering in the SdS spacetime. Finally, we study the Gaussian quantum steering in the scenario of effective equilibrium temperature. We show that quantum steering reduces monotonically with the effective temperature but now increases monotonically with the Hawking temperature of the black hole, which banishes the belief that the Hawking effect can only destroy quantum steering.

One to many one-way control in quadripartite asymmetric Einstein-Podolsky-Rosen steering

Einstein–Podolsky–Rosen (EPR) steering is different from quantum entanglement because of its unique asymmetry. Multipartite asymmetric EPR steering can break through one-to-one monogamy steering and achieve one to many one-way steering. That is to say, the state of one part can steer the other rest parts simultaneously, while the other parts cannot steer this part. Here, a scheme is proposed to generate one to many one-way steering by optical parametric amplification cascaded with a sum-frequency generation process. One to many non-monogamy EPR steering, such as one to two and one to three one-way steering are demonstrated based on the criterion for asymmetric EPR steering. It is also find that different kinds of asymmetric EPR steering can be obtained by choosing different nonlinear parameters. This non-monogamous one to many quantum control has potential application in constructing quantum networks and realizing one-way quantum computing.

Manipulating the direction of one-way steering in an optomechanical ring cavity

Quantum steering refers to the apparent possibility of exploiting nonseparable quantum correlations to remotely influence the quantum state of an observer via local measurements. Different from entanglement and Bell nonlocality, quantum steering exhibits an inherent asymmetric property, which makes it relevant for many asymmetric quantum information processing tasks. Here, we study Gaussian quantum steering between two mechanical modes in an optomechanical ring cavity. Using experimentally feasible parameters, we show that the state of the two considered modes can exhibit two-way steering and even one-way steering. Instead of using unbalanced losses or noises, we propose a simple practical way to control the direction of one-way steering. A comparative study between the steering and entanglement of the studied modes shows that both steering and entanglement undergo a sudden death-like behavior. In particular, steering is found more fragile against thermal noise remaining constantly upper-bounded by entanglement. The proposed scheme may be meaningful for one-sided device-independent quantum key distribution, where the security of such protocol depends fundamentally on the direction of steering.

Entanglement enhancement and EPR steering based on a PT-symmetric-like cavity-opto-magnomechanical hybrid system.

We investigate the enhancement of entanglement and EPR steering in a parity-time(PT-) symmetric-like cavity-opto-magnomechanical system. The system consists of an optical cavity, a magnon mode in a ferromagnetic crystal, a phonon mode, and a microwave cavity. Our findings demonstrate that microwave-cavity gain significantly boosts distant quantum entanglement and greatly improves the robustness of bipartite entanglement against environment temperature. Additionally, we observe an enhancement of tripartite entanglement within the system and uncover the phenomenon of entanglement transfer. Notably, we also achieve one-way steering and two-way asymmetric steering in the system. This study offers insights into the integration of traditional optomechanics and cavity magnomechanics, presenting a novel approach to manipulate asymmetric quantum steering between two distant macroscopic objects. The implications of our research extend to the fields of quantum state preparation and quantum information.

Entanglement generation and steering implementation in a double-cavity-magnon hybrid system.

We demonstrate a scheme for the generation of bipartite and tripartite entanglement, as well as he implementation of stable and controllable long-distance one-way and asymmetric two-way steering in a cavity-magnon hybrid system. This system consists of a magnon mode and two coupled microwave cavities. The first cavity is driven by a flux-driven Josephson parametric amplifier, which generates squeezed vacuum fields, and is coupled to the other cavity through optical tunneling interaction. The second cavity and magnon mode are coupled through magnetic dipole interaction. We find that under weak coupling between the two cavities, and strong coupling between the second cavity and magnon mode, remote controllable one-way steering and tripartite entanglement can be achieved. Our scheme may have potential applications in quantum information.

Controlling magnon-magnon entanglement and steering by atomic coherence.

Here we show that it is possible to control magnon-magnon entanglement in a hybrid magnon-atom-cavity system based on atomic coherence. In a four-level V-type atomic system, two strong fields are applied to drive two dipole-allowed transitions and two microwave cavity modes are coupled with two dipole forbidden transitions as well as two magnon modes simultaneously. It is found that the stable magnon-magnon entanglement, one-way steering and two-way EPR steering can be generated and controlled by atomic coherence according to the following two points: (i) the coherent coupling between magnon and atoms is established via exchange of virtual photons; (ii) the dissipation of magnon mode is dominant over amplification since one of the atomic states mediated one-channel interaction always keeps empty. The coherent control of magnon-magnon correlations provides an effective approach to modify macroscopic quantum effects using the laser-driven atomic systems.

Unlimited One-Way Steering.

This work explores the asymmetry of quantum steering in a setup using high-dimensional entanglement. We construct entangled states with the following properties: (i)one party (Bob) can never steer the state of the other party (Alice), considering the most general measurements, and (ii)Alice can strongly steer the state of Bob, in the sense of demonstrating genuine high-dimensional steering. In other words, Alice can convince Bob that they share an entangled state of arbitrarily high Schmidt number, while Bob can never convince Alice that the state is even simply entangled. In this sense, one-way steering can become unlimited. A key result for our construction is a condition for the joint measurability of all high-dimensional measurements subjected to the combined effect of noise and loss, which is of independent interest.