作者机构：
[Hu, Xiangming; Xu, Jun; Gou, Chengdeng] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM ] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
摘要：
Spin twisting is generally not incompatible with steady-state atomic coherence because spin twisting as a representative kind of parametric processes is based on far-off-resonant atom-field interactions while the steady-state atomic coherence is achieved mainly by resonant interactions. Here we propose a resonant plus far-off-resonant scheme to generate the compatibility. The resonant part uses coherent population trapping (CPT) for steady-state maximal atomic coherence, while the far-off-resonant part utilizes Stark shift for a nonlinear response in analog with the motion of a cavity mirror under radiation pressure. The compatible combination CPT with the spin optodymanics analog to cavity optomechanics leads to the spin one- or two-axis-twisting together with steady-state maximal atomic coherence. The general conditions and the parameter regimes for the compatibility are analyzed. This scheme illustrates that the combination of CPT with Stark shift provides an efficient way for the compatibility of the spin twisting squeezing with steady-state maximal atomic coherence.
作者机构：
[Tan, Wei-Jun; Wu, Qing-Lin; Wu, QL; Hu, Xiang-Ming; Zhong, Zi-Rui; Chen, Yue] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Cent China Normal Univ, China Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Wu, QL ] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
Weak measurement has been proven to amplify the detection of changes in meters while discarding most photons due to the low probability of postselection. Previous power-recycling schemes enable the failed postselection photons to be repeatedly selected, thus overcoming the inefficient postselection and increasing the precision of detection. In this study, we focus on the polarization-based weak value angular-velocity measurement and introduce three cyclic methods to enhance the accuracy of detecting time shifts in a Gaussian beam: power-recycling, signal -recycling, and dual -recycling schemes. By incorporating one or two partially transmitting mirrors into the system, both the power and the signal-to-noise ratio of the detected light are substantially enhanced. Compared to nonpolarization schemes, polarization-based approaches offer several advantages, including lower optical loss, unique cyclic directions, and a wider optimal region. These features effectively reduce crosstalk among different light paths and theoretically eliminate the walk -off effect, thus yielding improvements in both theoretical performance and application.
摘要：
In this paper, we propose an interesting scheme to generate antibunched N-photon bundles from dark states by using a single-atom cavity quantum electrodynamics system. The dispersive coupling between the atom and cavity introduces a Stark shift to one of the ground states, while the resonant coupling, along with a control field, forms a coherent N-excitation dark state assisted by the shift. Consequently, super-Rabi oscillation is established between the vacuum state and the N-excitation dark state when a probe field weakly couples to two ground states, enabling antibunched N-photon bundle emission within long-lived atomic coherence. As a byproduct, the generated high-efficiency single-photon source with a large mean photon number and high fidelity is of great value in quantum information processing.
作者机构：
[Chengdeng Gou; Xiangming Hu; Jun Xu] College of Physical Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China;[Fei Wang] School of Science, Hubei University of Technology, Wuhan 430068, People's Republic of China
摘要：
We show that the hybrid magnon-photon bundle emission is possible to generate by employing a three-level Δ -type superconducting artificial atom. The single atom is dispersively coupled with two microwave cavities, one of which simultaneously couples to a yttrium iron garnet (YIG) sphere via the magnetic dipole interaction. Based on the virtual photon exchange, the indirect magnon-atom interaction is established with flexibly tunable coupling strength, thus leading to the consecutive emission of hybrid magnon-photon pairs. The super-Rabi oscillation and Purcell effect make such a hybrid bundle possible in the present three-level system, which is difficult to achieve in the two-level system. The present scheme may find potential applications in quantum information processing and quantum sensing technology.
作者机构：
[Hu, Xiangming; Gou, Chengdeng] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM ] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
摘要：
In this paper we propose a scheme for achieving simultaneous nonreciprocal photon blockade for two coupled spinning resonators, one of which contains an optical parametric amplifier (OPA). Rotating two resonators gives rise to opposite Sagnac-Fizeau shifts for input from different ends. Depending on the opposite shifts, quantum destructive interference emerges and disappears in two-photon excitation. The emergence of destructive interference results in photon blockade in two resonators simultaneously for one end input, while the lack of complete destructive interference makes the blockade disappear for the other end input. The simultaneous nonreciprocal blockade is tunable by controlling the amplitude of the probe field and the driving field applied on the OPA. Our work paves the way to develop simultaneous nonreciprocal single-photon devices in multiple modes, which have potential applications in multichannel topological and chiral quantum technologies.
期刊：
New Journal of Physics,2023年25(6):063016 ISSN：1367-2630
通讯作者：
Hu, XM
作者机构：
[Hu, Xiangming; Chen, Junyu; Xu, Jun; Hu, Liang; Kong, Deyi] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM ] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
关键词：
spin two-axis-twisting;coherent population trapping;cavity QED
摘要：
We present a spin two-axis-twisting mechanism via coherent population trapping (CPT) based atom–photon interactions. CPT happens and the atoms are trapped in the dark state (coherent superposition of two ground states) when the ground states are resonantly coupled to a common excited state. Close to CPT, the atoms behave as two dark-state based spins, which interact with the common cavity vacuum fields. The otherwise nonexistent interaction is created between them and is identified to be responsible for the two-axis-twisting of the ground state spin. The essential difference from the previous schemes is the compatibility of the twisting spin squeezing with the resonant atom-light interaction. The CPT resonant unit serves as a kind of new ingredients for the quantum networks.
期刊：
Results in Physics,2023年52:106818 ISSN：2211-3797
通讯作者：
Hu, XM;Wang, Fei;Kong, DY
作者机构：
[Xu, Jun; Hu, Xiangming] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.;[Kong, Deyi; Wang, Fei; Wang, F] Hubei Univ Technol, Sch Sci, Wuhan 430068, Peoples R China.
通讯机构：
[Kong, DY ; Wang, F] H;[Hu, XM ] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.;Hubei Univ Technol, Sch Sci, Wuhan 430068, Peoples R China.
关键词：
Higher-order squeezing;Magnon;Superconducting artificial atom
摘要：
We propose an efficient scheme to realize almost perfect higher-order squeezing of two YIG spheres via microwave-mediated magnon–atom interactions. It is assumed that two microwave cavity modes are coupled to two YIG spheres by the magnetic dipole interaction and a superconducting artificial atom by the electric dipole interaction, respectively. When the microwave cavity fields are tuned to be far detuned from the dressed atomic Rabi sidebands and the magnon frequencies, the coherent coupling between two magnons and the artificial atom can be established via virtual photon exchange. We find that a pair of Bogoliubov modes composed of two magnon modes are cooled to the vacuum state through the atomic engineered dissipation, resulting in an ideal two-mode higher-order squeezing state of the YIG spheres. The solid-state device may find realistic applications in high-precision measurement and quantum sensing technology.
作者机构：
[Deyi Kong; Jun Xu; Ya Tian; Xiangming Hu] College of Physical Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China;[Fei Wang] School of Science, Hubei University of Technology, Wuhan 430068, People's Republic of China
摘要：
We propose a scheme to generate remote asymmetric Einstein-Podolsky-Rosen (EPR) steering of two magnon modes in a hybrid ferromagnet-superconductor system. In our scheme, the indirect coherent coupling between two distant magnons and a Δ -type superconducting atom is established via exchange of virtual photons in two dispersive cavities. As a consequence, the artificial atom acting as a reservoir can produce asymmetrical magnon-magnon steering via a single dissipation channel. Interestingly, we find that the steering directivity is determined by cooling either Bogoliubov mode selectively rather than increasing the extra noise as in conventional schemes. This provides a novel idea to prepare remote EPR steering in solid devices, which may find potential applications in quantum information processing.
作者机构：
[Gou, Chengdeng; Hu, Xiangming] College of Physical Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China;[Wang, Fei] School of Science, Hubei University of Technology, Wuhan 430068, People's Republic of China
摘要：
In this paper we propose an efficient scheme to continuously generate two-mode two-photon bundles by using a three-level atomic system, in which two correlated channels are created for the bundle emission in different modes. It is shown that the antibunching effect not only happens between the same modes but also between two different modes. While the former is due to the dominance of cavity decay over atomic decay, the latter is based on the atomic coherence between the two final states of bundle emission. The antibunched two-mode two-photon bundles are achievable in a wide range of parameters and robust against environmental noise. This scheme provides a kind of photon sources for two-signal-based applications such as quantum information processing, high-precision metrology, and ultrasensitive biosensing.
作者机构：
[Hu, Xiangming; Xu, Jun; Hu, Liang; Kong, Deyi] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
摘要：
In general, a magnon does not interact directly with an atom. Here we present a scheme to generate coherent coupling between two magnons and a superconducting artificial atom via exchange of virtual photons in dispersive cavities. By probing into the induced magnon-atom interactions, we identify the two-magnon process, which causes almost perfect two-mode squeezing and entanglement of the two magnons for specific conditions. The quantum entanglement of the magnon modes in two massive ferrimagnets survives at the steady state and represents genuinely macroscopic quantum state. Our work offers an interesting alternative in designing experiments for generating the coherent coupling between the magnons and the atom. It finds broad applications in the investigation of macroscopic quantum effects and the preparation of quantum devices.
摘要：
In this paper, we investigate the light-bullet dynamics during femtosecond laser filamenation in an anomalous dispersion regime based on the experimentally observed blueshifted resonant radiation (RR) in fused silica. A numerical simulation is performed and well reproduces the pronounced asymmetric feature of the RR spectra. By applying a time-frequency analysis to the propagating laser field, this specific spectral feature is found to be closely connected to the positively chirped property of RR in the time domain. In the context of the effective three-wave mixing model, this temporal chirp character of the RR is ascribed to the variable phase-matching conditions, which can be traced back to the accelerative propagation of the light bullet during its formation. Our work provides a deep understanding of the spatiotemporal dynamics of femtosecond laser-pulse propagation in condensed media.
