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Jie-Qiao Liao

Publications and source records attributed to Jie-Qiao Liao.

At least 37 records · Page 2Linked to original sources
arXiv2024

Simultaneous ground-state cooling of two levitated nanoparticles by coherent scattering

Simultaneous ground-state cooling of two levitated nanoparticles is a crucial prerequisite for investigation of macroscopic quantum effects such as quantum entanglement and quantum correlation involving translational motion of particles. Here we consider a coupled cavity-levitated-particle system and present a detailed derivation of its Hamiltonian. We find that the $y$-direction motions of the two particles are decoupled from the cavity field and both the $x$- and $z$-direction motions, and that the $z$-direction motions can be further decoupled from the cavity field and the $x$-direction motions by choosing proper locations of the particles. We study the simultaneous cooling of these mechanical modes in both the three-mode and five-mode cavity-levitated optomechanical models. It is found that there exists the dark-mode effect when the two tweezers have the same powers, which suppress the simultaneous ground-state cooling. Nevertheless, the simultaneous ground-state cooling of these modes can be realized by breaking the dark-mode effect under proper parameters. Our system provides a versatile platform to study quantum effects and applications in cavity-levitated optomechanical systems.

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arXiv2024

Manipulating Topological Polaritons in Optomechanical Ladders

We propose to manipulate topological polaritons in optomechanical ladders consisting of an optical Su-Schrieffer-Heeger (SSH) chain and a mechanical SSH chain connected through optomechanical (interchain) interactions. We show that the topological phase diagrams are divided into six areas by four boundaries and that there are four topological phases characterized by the Berry phases. We find that a topologically nontrivial phase of the polaritons is generated by the optomechanical interaction between the optical and mechanical SSH chains even though they are both in the topologically trivial phases. Counter-intuitively, six edge states appear in one of the topological phases with only two topological nontrivial bands, and some edge states are localized near but not at the boundaries of an open-boundary ladder. Moreover, a two-dimensional Chern insulator with higher Chern numbers is simulated by introducing proper periodical adiabatic modulations of the driving amplitude and frequency. Our work not only opens a route towards topological polaritons manipulation by optomachanical interactions, but also will exert a far-reaching influence on designing topologically protected polaritonic devices.

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arXiv2024

Entangling two giant atoms via a topological waveguide

The entanglement generation of two two-level giant atoms coupled to a photonic waveguide, which is formed by a Su-Schrieffer-Heeger (SSH) type coupled-cavity array is studied. Here, each atom is coupled to the waveguide through two coupling points. The two-atom separate-coupling case is studied, and 16 coupling configurations are considered for the coupling-point distributions between the two atoms and the waveguide. Quantum master equations are derived to govern the evolution of the two atoms and characterize atomic entanglement by calculating the concurrence of the two-atom states. It is found that the two giant-atom entanglement depends on the coupling configurations and the coupling-point distance of the giant atoms. In particular, the entanglement dynamics of the two giant atoms in 14 coupling configurations depend on the dimerization parameter of the SSH waveguide. According to the self-energies of the two giant atoms, it is found that ten of these 16 coupling configurations can be divided into five pairs. It is also showed that the delayed sudden birth of entanglement between the two giant atoms is largely enhanced in these five pairs of coupling configurations. This work will promote the study of quantum effects and coherent manipulation in giant-atom topological-waveguide-QED systems.

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arXiv2023

Dark-Mode Theorems for Quantum Networks

We propose and prove two theorems for determining the number of dark modes in linear two-component quantum networks composed of two types of bosonic modes. This is achieved by diagonalizing the two sub-networks of the same type of modes, mapping the networks to either a standard or a thick arrowhead matrix, and analyzing the linear dependence and independence between the column vectors associated with degenerate normal modes in the coupling matrix. We confirm the two theorems by checking the simultaneous ground-state cooling of the mechanical modes in linearized optomechanical networks. These results also work for linear fermionic networks and other networks described by quadratic coupled-mode Hamiltonian. The present method can be extended to study the dark-state effect in driven atom systems and to construct large decoherence-free subspaces for processing quantum information. This work will initiate the studies on dynamical, transport, and statistical properties of linear networks with decoupled subspaces.

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arXiv2023

Two-mode correlated multiphoton bundle emission

The preparation of correlated multiphoton sources is an important research topic in quantum optics and quantum information science. Here, two-mode correlated multiphoton bundle emission in a nondegenerate multiphoton Jaynes-Cummings model, which is comprised of a two-level system coupled with two cavity modes is studied. The two-level system is driven by a near-resonant strong laser such that the Mollow regime dominates the physical processes in this system. Under certain resonance conditions, a perfect super-Rabi oscillation between the zero-photon state $|0\rangle_{a}|0\rangle_{b}$ and the ($n+m$)-photon state $|n\rangle_{a}|m\rangle_{b}$ of the two cavity modes can take place. Induced by the photon decay, the two-mode correlated multiphoton bundle emission occurs in this system. More importantly, the results show that there is an antibunching effect between the strongly-correlated photon bundles, so that the system behaves as an antibunched ($n+m$)-photon source. The work opens up a route towards achieving two-mode correlated multiphoton source device, which has potential applications in modern quantum technology.

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arXiv2023

Anti-parity-time symmetry hidden in a damping linear resonator

Phase transition from the over-damping to under-damping states is a ubiquitous phenomenon in physical systems. However, what kind of symmetry is broken associated with this phase transition remains unclear. Here, we discover that this phase transition is determined by an anti-parity-time (anti-$\mathcal{PT}$) symmetry hidden in a single damping linear resonator, which is significantly different from the conventional anti-$\mathcal{PT}$-symmetric systems with two or more modes. We show that the breaking of the anti-$\mathcal{PT}$ symmetry yields the phase transition from the over-damping to under-damping states, with an exceptional point (EP) corresponding to the critical-damping state. Moreover, we propose an optomechanical scheme to show this anti-$\mathcal{PT}$ symmetry breaking by using the optical spring effect in a quadratic optomechanical system. We also suggest an optomechanical sensor with the sensitivity enhanced significantly around the EPs for the anti-$\mathcal{PT}$ symmetry breaking. Our work unveils the anti-$\mathcal{PT}$ symmetry hidden in damping oscillations and hence opens up new possibilities for exploiting wide anti-$\mathcal{PT}$ symmetry applications in single damping linear resonators.

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arXiv2023

Fast Generation of High-Fidelity Mechanical Non-Gaussian States via Additional Amplifier and Photon Subtraction

Non-Gaussian states (NGSs) with higher-order correlation properties have wide-range applications in quantum information processing. However, the generation of such states with high quality still faces practical challenges. Here, we propose a protocol to faithfully generate two types of mechanical NGSs, i.e., Schrödinger cat states and Fock states, in open optomechanical systems, even when the cooperativity is smaller than one ($g^2/κγ<1$). In contrast to the usual scheme, a short squeezed field is pumped to rapidly entangle with a mechanical resonator via a beam-splitter-like optomechanical interaction, effectively reducing the mechanical decoherence. Furthermore, by performing an additional amplifier and a following multi photon subtraction on the entangled optical field, one can selectively obtain the high-fidelity mechanical cat and Fock states. This protocol is robust to various imperfections, allowing it to be implemented with state-of-the-art experimental systems with close to unit fidelity. Moreover, it can be extended to generate a four-component cat state and provide possibilities for future quantum applications of NGSs.

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arXiv2023

Generation of two-giant-atom entanglement in waveguide-QED systems

We study the generation of quantum entanglement between two giant atoms coupled to a one-dimensional waveguide. Since each giant atom interacts with the waveguide at two separate coupling points, there exist three different coupling configurations in the two-atom waveguide system: separated, braided, and nested couplings. Within the Wigner-Weisskopf framework for single coupling points, the quantum master equations governing the evolution of the two giant atoms are obtained. For each coupling configuration, the entanglement dynamics of the two giant atoms is studied, including the cases of two different atomic initial states: single- and double-excitation states. It is shown that the generated entanglement depends on the coupling configuration, phase shift, and atomic initial state. For the single-excitation initial state, there exists steady-state entanglement for these three couplings due to the appearance of the dark state. For the double-excitation initial state, an entanglement sudden birth is observed via adjusting the phase shift. In particular, the maximal entanglement for the nested coupling is about one order of magnitude larger than those of separate and braided couplings. In addition, the influence of the atomic frequency detuning on the entanglement generation is studied. This work can be utilized for the generation and control of atomic entanglement in quantum networks based on giant-atom waveguide-QED systems, which have wide potential applications in quantum information processing.

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arXiv2023

Controllable generation of mechanical quadrature squeezing via dark-mode engineering in cavity optomechanics

Quantum squeezing is an important resource in modern quantum technologies, such as quantum precision measurement and continuous-variable quantum information processing. The generation of squeezed states of mechanical modes is a significant task in cavity optomechanics. Motivated by recent interest in multimode optomechanics, it becomes an interesting topic to create quadrature squeezing in multiple mechanical resonators. However, in the multiple-degenerate-mechanical-mode optomechanical systems, the dark-mode effect strongly suppresses the quantum effects in mechanical modes. Here we study the generation of mechanical squeezing in a two-mechanical-mode optomechanical system by breaking the dark-mode effect with the synthetic-gauge-field method. We find that when the mechanical modes work at a finite temperature, the mechanical squeezing is weak or even disappeared due to the dark-mode effect, while the strong mechanical squeezing can be generated once the dark-mode effect is broken. In particular, the thermal-phonon-occupation tolerance of the mechanical squeezing is approximately three orders of magnitude larger than that without breaking the dark-mode effect. We also generalize this method to break the dark modes and to create the mechanical squeezing in a multiple-mechanical-mode optomechanical system. Our results describe a general physical mechanism and pave the way towards the generation of noise-resistant quantum resources.

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arXiv2023

Chiral and nonreciprocal single-photon scattering in a chiral-giant-molecule waveguide-QED system

We study chiral and nonreciprocal single-photon scattering in a chiral-giant-molecule waveguide-QED system. Here, the giant molecule consists of two coupled giant atoms, which interact with two linear waveguides, forming a four-port quantum device. We obtain the exact analytical expressions of the four scattering amplitudes using a real-space method. Under the Markovian limit, we find that the single-photon scattering behavior is determined by the coupling strength between the giant atoms and the waveguides, the coupling strength between the two giant atoms, and the nondipole effect caused by the phase accumulation of photons travelling between the coupling points. It is also found that chiral and nonreciprocal single-photon scattering can be realized by introducing the chiral coupling to break the symmetry in the coupling configuration between the giant molecule and the waveguides. In addition, an ideal chiral emitter-waveguide coupling enables a directional single-photon routing. In the non-Markovian regime, the scattering spectra are characterized by more abundant structures with multiple peaks and dips. In particular, we demonstrate that the non-Markovian retarded effect can induce the nonreciprocal single-photon scattering. Our results have potential applications in the design of optical quantum devices involving giant atoms, which can provide an efficient platform for studying chiral quantum optics.

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arXiv2023

Giant-atom entanglement in waveguide-QED systems including non-Markovian effect

We study the generation of quantum entanglement between two giant atoms coupled to a common one-dimensional waveguide. Here each giant atom interacts with the waveguide at two separate coupling points. Within the Wigner-Weisskopf framework for single coupling points, we obtain the time-delayed quantum master equations governing the evolution of the two giant atoms for three different coupling configurations: separated, braided, and nested couplings. For each coupling configuration, we consider both the Markovian and non-Markovian entanglement dynamics of the giant atoms, which are initially in two different separable states: single- and double-excitation states. Our results show that the generated entanglement depends on the phase shift, time delay, atomic initial state, and the coupling configuration. For the single-excitation initial state, there exists the steady-state entanglement for each coupling in both the Markovian and non-Markovian regimes due to the appearance of the dark state. For the double-excitation initial state, we observe entanglement sudden birth via adjusting the phase shift in both regimes. In particular, the maximally achievable entanglement for the nested coupling is about one order of magnitude larger than those of separate and braided couplings. We also find that the maximal entanglement for these three coupling configurations can be enhanced in the case of small time delays. This work can be utilized for the generation and control of entanglement in quantum networks based on giant-atom waveguide-QED systems, which have wide potential applications in quantum information processing.

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arXiv2023

Dynamical $N$-photon bundle emission

Engineering multiphoton resources is of importance in quantum metrology, quantum lithography, and biological sensing. Here we propose a concept of dynamical emission of $N$ strongly-correlated photons. This is realized in a circuit quantum electrodynamical system driven by two Gaussian-pulse sequences. The underlying physical mechanism relies on the stimulated Raman adiabatic passage that allows efficient and selective preparation of target multiphoton states. Assisted by the photon decay, a highly pure $N$-photon bundle emission takes place in this system. In particular, the dynamical $N$-photon bundle emission can be tuned by controlling the time interval between consecutive pulses so that the device behaves as an $N$-photon gun, which can be triggered on demand. Our work opens up a route to achieve multiphoton source devices, which have wide potential applications in quantum information processing and quantum metrology.

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arXiv2023

Multiple-photon bundle emission in the $n$-photon Jaynes-Cummings model

We study the multiple-photon bundle emission in the $n$-photon Jaynes-Cummings model composed of a two-level system coupled to a single-mode optical field via the $n$-photon exciting process. Here, the two-level system is strongly driven by a near-resonant monochromatic field, and hence the system can work in the Mollow regime, in which a super-Rabi oscillation between the zero-photon state and the $n$-photon state can take place under proper resonant conditions. We calculate the photon number populations and the standard equal-time high-order correlation functions, and find that the multiple-photon bundle emission can occur in this system. The multiple-photon bundle emission is also confirmed by investigating the quantum trajectories of the state populations and both the standard and generalized time-delay second-order correlation functions for multiple-photon bundle. Our work paves the way towards the study of multiple-photon quantum coherent devices, with potential application in quantum information sciences and technologies.

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arXiv2023

Quantum thermalization and thermal entanglement in the open quantum Rabi model

We study quantum thermalization and thermal entanglement in the open quantum Rabi model (QRM), in which a two-level system and a single-mode bosonic field are coupled to either two individual heat baths or a common heat bath. By treating the QRM as an effective multilevel system and deriving global quantum master equations in the eigenstate representation of the QRM, we study the physical conditions for quantum thermalization of the open QRM. It is found that, in the individual heat-bath case, the QRM can only be thermalized when either the two heat baths have the same temperature or the QRM is only coupled to one of the two baths. In the common heat-bath case, differently, the QRM can always be thermalized. We also study thermal entanglement of the QRM in both the resonant- and non-resonant coupling cases. The logarithmic negativity for the thermal state of the QRM is obtained in a wide parameter space, ranging from the low- to high-temperature limits, and from the weak- to deep-strong-coupling regimes. This work paves the way towards the study of quantum effects in nonequilibrium ultrastrongly-coupled light-matter systems.

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arXiv2022

Non-Markovian disentanglement dynamics in double-giant-atom waveguide-QED systems

We study the disentanglement dynamics of two giant atoms coupled to a common one-dimensional waveguide. We focus on the non-Markovian retarded effect in the disentanglement of the two giant atoms by taking the photon transmission time into account. By solving the time-delayed equations of motion for the probability amplitudes, we obtain the evolution of the entanglement of the two giant atoms, which are initially in the maximally entangled states in the single-excitation space. It is found that the retardation-induced non-Markovianity leads to non-exponential decay and revivals of entanglement. Concretely, we consider separate-, braided-, and nested-coupling configurations, and find that the disentanglement dynamics in these configurations exhibits different features. We demonstrate that the steady-state entanglement depends on the time delay under certain conditions in these three coupling configurations. We also study the dependence of the disentanglement of the two giant atoms on both the detuning effect and the initial-state phase effect. In addition, we consider the disentanglement dynamics of the two giant atoms, which are initially in the state superposed by zero-excitation and two-excitation components. This work will pave the way for the generation of stationary entanglement between two giant atoms, which may have potential applications in the construction of large-scale quantum networks based on the giant-atom waveguide-QED systems.

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arXiv2022

Thermal-noise-resistant optomechanical entanglement via general dark-mode control

Quantum entanglement not only plays an important role in the study of the fundamentals of quantum theory, but also is considered as a crucial resource in quantum information science. The generation of macroscopic entanglement involving multiple optical and mechanical modes is a desired task in cavity optomechanics. However, the dark-mode effect is a critical obstacle against the generation of quantum entanglement in multimode optomechanical systems consisting of multiple degenerate or near-degenerate mechanical modes coupled to a common cavity mode. Here we propose an auxiliary-cavity-mode method to enhance optomechanical entanglement in a multimode optomechanical system by breaking the dark-mode effect. We find that the introduction of the auxiliary cavity mode not only assists the entanglement creation between the cavity mode and the mechanical modes, but also improves the immunity of the optomechanical entanglement to the thermal excitations by about three orders of magnitude. We also study the optomechanical entanglement in the network-coupled optomechanical system consisting of two mechanical modes and two cavity modes. By analyzing the correspondence between the optomechanical entanglement and the dark-mode effect, we find that optomechanical entanglement can be largely enhanced once the dark mode is broken. In addition, we study the mechanical entanglement and find that it is negligibly small. We also present some discussions on the experimental implementation with a microwave optomechanical setup, on the relationship between the dark-mode-breaking mechanism and the center-of-mass and relative coordinates, and on the explanation of the important role of the dark-mode breaking in the enhancement of optomechanical entanglement. Our results pave the way towards the preparation of entangled optomechanical networks and noise-resistant quantum resources.

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arXiv2022

Noise-Tolerant Optomechanical Entanglement via Synthetic Magnetism

Entanglement of light and multiple vibrations is a key resource for multi-channel quantum information processing and memory. However, entanglement generation is generally suppressed, or even fully destroyed, by the dark-mode (DM) effect induced by the coupling of multiple degenerate or near-degenerate vibrational modes to a common optical mode. Here we propose how to generate optomechanical entanglement via \emph{DM breaking} induced by synthetic magnetism. We find that at nonzero temperature, light and vibrations are \emph{separable} in the DM-unbreaking regime but \emph{entangled} in the DM-breaking regime. Remarkably, the threshold thermal phonon number for preserving entanglement in our simulations has been observed to be up to \emph{three} orders of magnitude stronger than that in the DM-unbreaking regime. The application of the DM-breaking mechanism to optomechanical networks can make noise-tolerant entanglement networks feasible. These results are quite general and can initiate advances in quantum resources with immunity against both dark modes and thermal noise.

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arXiv2022

Multimode optomechanical cooling via general dark-mode control

The dark-mode effect is a stubborn obstacle for ground-state cooling of multiple degenerate mechanical modes optomechanically coupled to a common cavity-field mode. Here we propose an auxiliary-cavity-mode method for simultaneous ground-state cooling of two degenerate or near-degenerate mechanical modes by breaking the dark mode. We find that the introduction of the auxiliary cavity mode not only breaks the dark-mode effect, but also provides a new cooling channel to extract the thermal excitations stored in the dark mode. Moreover, we study the general physical-coupling configurations for breaking the dark mode in a generalized networkcoupled four-mode optomechanical system consisting of two cavity modes and two mechanical modes. We find the analytical dark-mode-breaking condition in this system. This method is general and it can be generalized to break the dark-mode effect and to realize the simultaneous ground-state cooling in a multiple-mechanicalmode optomechanical system. We also demonstrate the physical mechanism behind the dark-mode breaking by studying the breaking of dark-state effect in the N-type four-level atomic system. Our results not only provide a general method to control various dark-mode and dark-state effects in physics, but also present an opportunity to the study of macroscopic quantum phenomena and applications in multiple-mechanical-resonator systems.

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