Abstract The main challenge in deterministic quantum state transfer (QST) between remote mechanical resonators is the local decoherence and the transmission losses in the communication channel. In the path of overcoming this limitation, here we employ a shortcut to adiabatic passage protocol to devise a fast and reliable evolution path between two remote mechanical modes in separate optomechanical systems (OMSs). A QST between the two nodes is conceived by engineering their coupling to an intermediate fiber optical channel. The coupling pulses are operated such that the dark eigenmode of the system is decoupled from the fiber modes and transitions to the bright modes are compensated for by counterdiabatic drives. We show that one obtains a QST with high fidelity for various Gaussian states. The efficiency is compared to that of adiabatic passage (AP) protocol in the presence of losses and noises. Our results show that while the AP protocol is very sensitive to the decoherence, the shortcut to adiabaticity provides a robust and fast QST even for small values of the coupling strength. The performance of both protocols are also investigated for the case of multimode fiber through numerical and an effective single-model model which is found by the elimination of off-resonant fiber modes. Our findings may pave the way for using OMSs in the realization of continuous-variable Gaussian QST.
Abstract The main challenge in deterministic quantum state transfer (QST) between remote mechanical resonators is the local decoherence and the transmission losses in the communication channel. In the path of overcoming this limitation, here we employ a shortcut to adiabatic passage protocol to devise a fast and reliable evolution path between two remote mechanical modes in separate optomechanical systems (OMSs). A QST between the two nodes is conceived by engineering their coupling to an intermediate fiber optical channel. The coupling pulses are operated such that the dark eigenmode of the system is decoupled from the fiber modes and transitions to the bright modes are compensated for by counterdiabatic drives. We show that one obtains a QST with high fidelity for various Gaussian states. The efficiency is compared to that of adiabatic passage (AP) protocol in the presence of losses and noises. Our results show that while the AP protocol is very sensitive to the decoherence, the shortcut to adiabaticity provides a robust and fast QST even for small values of the coupling strength. The performance of both protocols are also investigated for the case of multimode fiber through numerical and an effective single-model model which is found by the elimination of off-resonant fiber modes. Our findings may pave the way for using OMSs in the realization of continuous-variable Gaussian QST.
The main challenge in deterministic quantum state transfer in long-distance quantum communications is the transmission losses in the communication channel. To overcome this limitation, here we use the adiabatic theorem and find a lossless evolution path between two remote mechanical modes. By adiabatic variation of the effective coupling strengths between the two nodes and the intermediate optical channel modes, we engineer a transmission path for the quantum state transfer that is decoupled from the decaying fiber modes. Using our proposed method we show that one obtains a quantum state transfer with high efficiency. Furthermore, to bypass the slow nature of the adiabatic process and its sensitivity to the mechanical damping and noise as well as the strength of the driving pulses, we develop the shortcut to adiabatic passage protocol for our proposed quantum state transfer. Our results show that the shortcut to adiabaticity provides an efficient and fast quantum state transfer even for small values of the coupling strength. We show that the performance of our protocol for long-distance quantum communications remains efficient for transferring the quantum states between two remote mechanical resonators being hundred meters apart.
Performing a faithful transfer of an unknown quantum state is a key challenge for enabling quantum networks. The realization of networks with a small number of quantum links is now actively pursued, which calls for an assessment of different state transfer methods to guide future design decisions. Here, we theoretically investigate quantum state transfer between two distant qubits, each in a cavity, connected by a waveguide, e.g., an optical fiber. We evaluate the achievable success probabilities of state transfer for two different protocols: standard wave packet shaping and adiabatic passage. The main loss sources are transmission losses in the waveguide and absorption losses in the cavities. While special cases studied in the literature indicate that adiabatic passages may be beneficial in this context, it remained an open question under which conditions this is the case and whether their use will be advantageous in practice. We answer these questions by providing a full analysis, showing that state transfer by adiabatic passage—in contrast to wave packet shaping—can mitigate the effects of undesired cavity losses, far beyond the regime of coupling to a single waveguide mode and the regime of lossless waveguides, as was proposed so far. Furthermore, we show that the photon arrival probability is in fact bounded in a trade-off between losses due to non-adiabaticity and due to coupling to off-resonant waveguide modes. We clarify that neither protocol can avoid transmission losses and discuss how the cavity parameters should be chosen to achieve an optimal state transfer.
Abstract Quantum state transfer between two nodes is a basic task of long-distance quantum communication. In this paper, we propose a general protocol to transfer quantum state between optical and microwave modes in a three-mode optomechanical system based on transitionless quantum driving. By choosing a well-designed path, the reversible transfer between optical and microwave modes can be achieved in the shorter time than adiabatic passage method. We further apply this idea for implementing the quantum state transfer between optical or microwave and mechanical modes. Numerical simulation results show that the protocol is robust against the cavity decay and mechanical damping. Therefore, this work provides a new method for quantum state transfer between two optical modes with distinct wavelengths in the optomechanical system, which may have great application prospect in quantum communication.
We propose a new approach for quantum state transfer (QST) between atomic ensembles separately trapped in two distant cavities connected by an optical fiber via adiabatic passage. The three-level Λ-type atoms in each ensemble dispersively interact with the nonresonant classical field and cavity mode. By choosing appropriate parameters of the system, the effective Hamiltonian describes two atomic ensembles interacting with “the same cavity mode” and has a dark state. Consequently, the QST between atomic ensembles can be implemented via adiabatic passage. Numerical calculations show that the scheme is robust against moderate fluctuations of the experimental parameters. In addition, the effect of decoherence can be suppressed effectively. The idea provides a scalable way to an atomic-ensemble-based quantum network, which may be reachable with currently available technology.
We propose a new approach for quantum state transfer(QST) between atomic ensembles separately trapped in two distant cavities connected by an optical fiber via adiabatic passage. The three-level Λ-type atoms in each ensemble dispersively interact with nonresonant classical field and cavity mode. By choosing appropriate parameters of system, effective Hamiltonian describes two atomic ensembles interacting with the same cavity mode and has a dark state. Consequently, QST between atomic ensembles can be implemented via adiabatic passage. Numerical calculations show that scheme is robust against moderate fluctuations of experimental parameters. In addition, effect of decoherence can be suppressed effectively. The idea provides a scalable way to an atomic-ensemble-based quantum network, which may be reachable with currently available technology.
Quantum information, as a comprehensive subject of quantum mechanics and information science, has a broad theoretical research value and application prospect. As a resource of quantum information, quantum entanglement has been studied thoroughly, which is not only significant to understand the features of quantum mechanics, but also of great value to the development of the method new quantum information processing. Therefore, the generation of entangled state is widely studied theoretically. In comparison to low-dimensional entangled states, multi-dimensional entangled states are not only safe but also efficient and error-tolerant for quantum computation. The adiabatic technique is one of the most widely used and proven techniques in quantum information science. The main advantages of this technique are that it is insensitive to the fluctuation of experimental parameters, and the interaction time of the system is not required to be controled accurately. However, limited by the adiabatic condition, it usually takes relatively long interaction time in scheme via adiabatic technique to achieve the target states. If the required evolution time is too long, the scheme may be useless. To overcome this problem, researchers have done a lot in the field of finding ways to shorten the long interaction time of adiabatic passage. Among these works, the technique named shortcuts to adiabatic passage is a successful work in this field and it has attracted a great deal of attention in recent years. In this paper, based on transitionless quantum driving to construct shortcuts to adiabatic passage, an efficient scheme to fast generate a four-dimensional entangled state of two-atom is proposed. The atoms are respectively trapped in the separate two-mode cavities which are connected by optical fiber. To achieve an alternative physically feasible system, the non-resonant dynamics is adopted to create a Hamiltonian which can exactly drive the system to evolve along the instantaneous eigenstates of the original Hamiltonian. As a result, if the system goes through adiabatic passage, it will evolve in the dark state, not transit to other states. Hence, using transitionless quantum driving to shortcuts to adiabatic passage, the evolutionary time in this scheme is much less than that in other schemes based on traditional adiabatic passage. The rigorous numerical simulations are conducted. The results show that with suitable pulsed laser parameters, this scheme is robust against decoherence arising from fiber decay, cavity decay and atomic spontaneous emission. Moreover, the scheme is more feasible in physics. That is, based on the proposed scheme, a high-fidelity four-dimensional entangled state of two-atom can be achieved.