Article
Optics
Shuang Zheng, Weizhen Yu, Weifeng Zhang
Summary: Notions drawn from non-Hermitian physics and parity-time (PT) symmetry have gained significant attention in photonics. In this study, a compact passive PT-symmetric grating is proposed on a silicon-on-insulator (SOI) platform, enabling asymmetric reflection and diffraction. The research provides a new perspective for exploring and creating complex on-chip PT-symmetric devices.
Article
Optics
Chang-Long Zhu, Yu-Long Liu, Lan Yang, Yu-Xi Liu, Jing Zhang
Summary: This study presents a mechanism for achieving synchronization of mechanical modes in two coupled optomechanical resonators with a parity-time (PT)-symmetric structure. It is shown that decreasing the coupling strength between the resonators can increase the degree of synchronization between mechanical modes. Additionally, the presence of stochastic noises near the exceptional point can enhance the synchronization of the system within a specific parameter regime.
PHOTONICS RESEARCH
(2021)
Article
Engineering, Electrical & Electronic
Hongji Wang, Yuechun Shi, Yitao Wu, Ziming Hong, Yuxin Ma, Haoyuan Wu, Xiaojun Zhu, Zhanghua Han, Xiangfei Chen
Summary: In this paper, a new configuration of narrow linewidth semiconductor lasers (NLSLs) based on a novel narrow-band reflector (NBR) is presented. By introducing a pi phase-shifted anti-symmetric Bragg grating (pi-ASBG) and a uniform grating reflector, the effective length of the Bragg grating is greatly increased, resulting in a much narrower linewidth compared to traditional NLSLs.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Yuanjiang Tang, Chao Liang, Xin Wen, Weipeng Li, An-Ning Xu, Yong-Chun Liu
Summary: We propose a PT-symmetric feedback method to narrow the linewidths of resonance systems, achieving remarkable linewidth narrowing and enhancement of measurement sensitivity. By transforming a dissipative resonance system into a PT-symmetric system, using a quadrature measurement-feedback loop, the method only requires a single resonance mode, greatly extending its scope of applications. In a thermal ensemble of atoms, we demonstrate a 48-fold narrowing of the magnetic resonance linewidth and a 22-times improvement in measurement sensitivity in magnetometry, opening new avenues for studying nonHermitian physics and high-precision measurements in resonance systems with feedback.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Huilai Zhang, Meiyu Peng, Xun-Wei Xu, Hui Jing
Summary: This study proposes a method to achieve a nonlinear anti-parity-time (APT) gyroscope by spinning an optical resonator. The results show that, compared to conventional devices, the sensitivity or optical mode splitting of the linear device can be magnified up to three orders. When the Kerr nonlinearity of the materials is included, the nonlinear gyroscope can detect weaker rotations, significantly lowering the detection threshold.
Article
Optics
C. N. Alexeyev, E. Barshak, B. P. Lapin, M. A. Yavorsky
Summary: This study investigates the propagation of optical vortices in coupled parity-time symmetric multimode fibers with equal gain and loss. The system is found to have two second-order exceptional points where the degenerate modes are odd and even Laguerre-Gaussian modes. The research examines the evolution of an arbitrary incoming superposition of Laguerre-Gaussian modes and demonstrates that a black hole state is formed on the orbital Poincare sphere beyond the lowest exceptional point.
Article
Physics, Multidisciplinary
Sebae Park, Dongjin Lee, Kyungdeuk Park, Heedeuk Shin, Youngsun Choi, Jae Woong Yoon
Summary: In this study, an optical anti-parity-time (APT) symmetric system was created using a conventional fiber to demonstrate photonic APT-symmetric effects, such as energy-difference conservation and synchronized power oscillation. The results provide a theoretical and experimental framework linking non-Hermitian physics with technologically important nonlinear fiberoptic interactions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Tiecheng Wang
Summary: We have introduced generalized temporal coupled-mode theory for PT-symmetric optical resonator, and used it to explain the Fano resonance in PT-symmetric photonic heterostructures. Our theory's predictions match well with the simulated results from the transfer matrix method, confirming its accuracy. In contrast to conventional Fano resonance in optical resonators with time-reversal symmetry, this Fano resonance allows for a much larger range of tunable scattering coefficient amplitudes, which can exceed one and approach infinity at a singular scattering point.
Article
Optics
Enes Seker, Babak Olyaeefar, Khalil Dadashi, Serdar Sengul, Mohammad Hosain Teimourpour, Ramy El-Ganainy, Abdullah Demir
Summary: We experimentally demonstrate a new type of electrically pumped, large-area edge-emitting lasers that exhibit high power emission and high-quality beam. By establishing quasi PT-symmetry between two coupled cavities, the effective volume of higher-order modes is enlarged, allowing for selective pumping and filtering out higher-order modes. This work provides clear evidence of the utility of PT-symmetry in building lasers with enhanced performance and useful output power levels.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Anant V. Varma, Sourin Das
Summary: By embedding N noninteracting spin-1/2 (PT-symmetric) degrees of freedom, it was demonstrated that the resulting Hermitian Hamiltonian of N + 1 spin halves includes all to all, q-body interaction terms. With finite entanglement in the eigenstates of the resulting cluster, the probability of post-selection of the additional spin-1/2 remains nonvanishing, crucial for practical embedding. This study's connection to a central spin model highlights the role of orthogonality catastrophe in protecting the additional spin-1/2 degree of freedom from decoherence.
Article
Optics
K. Tamilselvan, A. Govindarajan, I. Inbavalli, T. Alagesan, M. Lakshmanan
Summary: In this article, we investigate the nontrivial characteristics of modulational instability in a system of Bragg gratings with saturable nonlinearity. By introducing an equal amount of gain and loss, we explore the additional degree of freedom due to the concept of PT symmetry. Our findings reveal that the dispersion relations for both the conventional and PT-symmetric cases contradict the typical signature of loop formation displayed by conventional Kerr and saturable systems. Through comprehensive analyses, we observe a variety of instability spectra and address the impact of physical parameters on the phenomenon of modulational instability in different PT-symmetric regimes.
Article
Physics, Multidisciplinary
Yu-Liang Fang, Jun-Long Zhao, Yu Zhang, Dong-Xu Chen, Qi-Cheng Wu, Yan-Hui Zhou, Chui-Ping Yang, Franco Nori
Summary: This study experimentally demonstrates single-qubit coherence flow in PT- and APT-symmetric systems using an optical setup. Different periodic oscillations of coherence are observed in the symmetry unbroken regime, with two complete coherence backflows in one period in the PT-symmetric system and one backflow in the APT-symmetric system. The phenomenon of stable value of coherence flow is observed in the symmetry broken regime, and most experimental data agree with theoretical results within one standard deviation, suggesting potential avenues for future research in the dynamics of coherence in PT- and APT-symmetric systems.
COMMUNICATIONS PHYSICS
(2021)
Article
Multidisciplinary Sciences
Javed Akram, Chao Zheng
Summary: In this study, we investigate the dynamics of entanglement in a PT-APT symmetric system for the first time. We also compare the entanglement dynamics in PT-PT symmetric systems, APT-APT symmetric systems, and PT-APT symmetric systems to gain further insights into non-Hermitian quantum systems and their environments. Our findings show that in the unbroken regime of the PT-APT symmetric system, entanglement oscillates with two different frequencies and can be well preserved for a long time when the non-Hermitian parts of the qubits are far from the exceptional points.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Xin-zhe Zhang, Ru-zhi Luo, J. I. N. G. Chen
Summary: This study shows that the time-averaged Poynting vector in parity-time (PT) symmetric coupled waveguides is always positive and cannot explain the phenomenon of stopped light at exceptional points (EPs). By considering the fields and Poynting vector in non-Hermitian systems as complex, a formula for the group velocity is proposed, which accurately explains the stopped light and fast-light effect at EPs. This research bridges the gap between classical electrodynamics and non-Hermitian physics, emphasizing the novelty of non-Hermitian optics.
Article
Optics
Ziyang Chen, Fuqiang Li, Cibo Lou
Summary: The experiment observed spatial rogue waves generated by a wide Gaussian beam in a saturated nonlinear system, with the probability of occurrence related to the evolution of the beam to the critical state of filament splitting, voltage fluctuations, and nonlinear breathing phenomenon. The statistics of rogue waves satisfy a long-tailed L-shaped distribution, indicating that the presence of high-frequency components and aggregation of low-frequency components are prerequisites for extreme events to occur.
CHINESE OPTICS LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Samit Kumar Gupta, Yi Zou, Xue-Yi Zhu, Ming-Hui Lu, Li-Jian Zhang, Xiao-Ping Liu, Yan-Feng Chen
ADVANCED MATERIALS
(2020)
Article
Physics, Applied
Xingping Zhou, Samit Kumar Gupta, Xueyi Zhu, Guangxu Su, Peng Zhan, Yongmin Liu, Zhuo Chen, Minghui Lu, Zhenlin Wang
PHYSICAL REVIEW APPLIED
(2020)
Article
Physics, Multidisciplinary
Arindam Saha, Amarendra K. Sarma
Summary: The study introduces a novel hybrid optomechanical system that achieves state transfer between cavity mode and qubit without actual interaction. The displacement of the mechanical oscillator induced by radiation pressure allows quantum information to be transferred without direct interaction, enabling perfect state transfer.
Article
Physics, Multidisciplinary
Dipti Kanika Mahato, A. Govindarajan, M. Lakshmanan, Amarendra K. Sarma
Summary: Optical rogue waves and their variants have been extensively studied in the context of optical fiber, with Kuznetsov-Ma breathers generated from rational solutions of the nonlinear Schrodinger equation with periodic modulation of the dispersion coefficient. The dynamics of these breathers can be controlled by selecting appropriate modulating parameters, and new breather-like solutions can evolve corresponding to higher-order rational solutions. Direct numerical simulations based on modulational instability confirm the analytical results, making the proposed system more feasible for experimental realization.
Article
Physics, Multidisciplinary
Sampreet Kalita, Subhadeep Chakraborty, Amarendra K. Sarma
Summary: Synchronization can be achieved in two optomechanical oscillators with a finite degree of quantum correlation, regardless of their configuration. The directionality of optical coupling plays a significant role in the synchronization behavior, affecting the variation of synchronization against the frequency detuning of the oscillators.
JOURNAL OF PHYSICS COMMUNICATIONS
(2021)
Article
Optics
Roson Nongthombam, Sampreet Kalita, Amarendra K. Sarma
Summary: We investigate the synchronization between a superconducting qubit and an external optical field in a hybrid electrooptomechanical system using the quantum trajectory method. Bistability is observed in the qubit's polarization vector, where the qubit rotates around the vector. With an increased number of trajectories, the qubit no longer displays bistability but still shows synchronization with reduced quantum fluctuations. This scheme can be applied for preparing and monitoring the state of the microwave qubit to an optical photon, which has potential applications in long-distance quantum communication. Additionally, it provides a platform for studying quantum synchronization.
Article
Optics
Sampreet Kalita, Pardeep Kumar, Rina Kanamoto, M. Bhattacharya, Amarendra K. Sarma
Summary: A recent proposal based on cavity optomechanics enables the sensing and manipulation of rotation in a bosonic ring condensate, with minimal destruction and in real time. In this study, we investigate coherent interference effects supported by this configuration and analyze the influence of atomic rotation on the transmission spectrum of a weak probe laser. Our results show that the narrow probe transmission profiles and group delay can be tuned by persistent currents, offering potential applications in atomtronics, sensing, and information processing.
Article
Optics
Ambaresh Sahoo, Amarendra K. Sarma
Summary: By tuning the coupling parameters of a non-Hermitian system, device sensitivity to small perturbations can be enhanced, and a phase transition in exceptional points can be achieved. The adjustable coupling also leads to a sharp change in sensitivity slope, enabling precise measurement of perturbations as a function of coupling.
Article
Optics
Sampreet Kalita, Saumya Shah, Amarendra K. Sarma
Summary: We propose an effective method for generating entangled and squeezed states in an optoelectromechanical system. By modulating the laser drive amplitude, voltage drive amplitude, and spring constant, we enhance the optoelectrical entanglement. The maximum amount of entanglement depends primarily on the voltage modulation. Additionally, we observe maximum squeezing and maximum entanglement windows when all three types of modulations are applied.
Article
Optics
Ambaresh Sahoo, Dipti Kanika Mahato, A. Govindarajan, Amarendra K. Sarma
Summary: We investigate switching dynamics in a PT-symmetric fiber coupler composed of a saturable nonlinear material as the core. Our findings show richer soliton switching dynamics than conventional counterparts, which may lead to ultrafast and efficient all-optical switching dynamics. Furthermore, we provide a suitable range of system and pulse parameters for practical realization of the coupler in all-optical switching devices and photonic circuits. The developed variational approach excellently predicts the numerical findings.
Article
Optics
Roson Nongthombam, Ambaresh Sahoo, Amarendra K. Sarma
Summary: A scheme for ground-state cooling of a mechanical resonator by simultaneously coupling it to a superconducting qubit and a cavity field is proposed, and it is found that hybrid cooling is more efficient under specific parameter choices.
Article
Physics, Multidisciplinary
Xueyi Zhu, Huaiqiang Wang, Samit Kumar Gupta, Haijun Zhang, Biye Xie, Minghui Lu, Yanfeng Chen
PHYSICAL REVIEW RESEARCH
(2020)
Review
Engineering, Electrical & Electronic
Hongfei Wang, Samit Kumar Gupta, Biye Xie, Minghui Lu
FRONTIERS OF OPTOELECTRONICS
(2020)
