Experimental observation of Dirac exceptional point

• URL: http://arxiv.org/abs/2503.08436v1
• Date: Tue, 11 Mar 2025 13:50:18 GMT
• Title: Experimental observation of Dirac exceptional point
• Authors: Yang Wu, Dongfanghao Zhu, Yunhan Wang, Xing Rong, Jiangfeng Du,
• Abstract summary: exceptional points (EPs) are crucial for comprehending emerging phenomena in materials and enabling innovative functionalities for devices.<n>Here we report the observation of a novel type of EP, named the Dirac EP, utilizing a nitrogen-vacancy center in diamond.<n>This exotic band topology enables the preservation of the symmetry when passing through, and makes it possible to achieve adiabatic evolution in non-Hermitian systems.
• Score: 12.138963580007283
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The energy level degeneracies, also known as exceptional points (EPs), are crucial for comprehending emerging phenomena in materials and enabling innovative functionalities for devices. Since EPs were proposed over half a century age, only two types of EPs have been experimentally discovered, revealing intriguing phases of materials such as Dirac and Weyl semimetals. These discoveries have showcased numerous exotic topological properties and novel applications, such as unidirectional energy transfer. Here we report the observation of a novel type of EP, named the Dirac EP, utilizing a nitrogen-vacancy center in diamond. Two of the eigenvalues are measured to be degenerate at the Dirac EP and remain real in its vicinity. This exotic band topology associated with the Dirac EP enables the preservation of the symmetry when passing through, and makes it possible to achieve adiabatic evolution in non-Hermitian systems. We examined the degeneracy between the two eigenstates by quantum state tomography, confirming that the degenerate point is a Dirac EP rather than a Hermitian degeneracy. Our research of the distinct type of EP contributes a fresh perspective on dynamics in non-Hermitian systems and is potentially valuable for applications in quantum control in non-Hermitian systems and the study of the topological properties of EP.

Related papers

• Exceptional-Point Dynamics [1.2499537119440243]
  Exceptional points (EPs) play a vital role in non-Hermitian (NH) systems, driving unique dynamical phenomena and promising innovative applications.<n>This work completes the dynamical investigation of NH physics, offers valuable insights into the nonunitary evolution at EPs, and further lays the foundation for engineering and exploiting EP-related devices and technologies.
  arXiv  Detail & Related papers  (2025-07-20T10:14:46Z)
• Unveiling the Self-Orthogonality at Exceptional Points in Driven $\mathcal{PT}$-Symmetric Systems [79.16635054977068]
  We explore the effect of self-orthogonality at exceptional points (EPs) in non-Hermitian Parity-Time-symmetric systems.<n>Using a driven three-band lattice model, we show that the Rabi frequency diverges as the system approaches an EP due to the coalescence of eigenstates.
  arXiv  Detail & Related papers  (2025-07-14T12:53:10Z)
• Unification of Exceptional Points and Transmission Peak Degeneracies in a Highly Tunable Magnon-Photon Dimer [41.94295877935867]
  This work presents a microwave magnon-photon dimer with near-universal tunability across all relevant parameters.<n>We show that two-dimensional EP and TPD configurations can be unified into a general theory and experimental framework.<n>Our formalism and experimental methods unify previous EP and TPD configurations and may lead to the realization of robust TPD-enhanced sensors.
  arXiv  Detail & Related papers  (2025-06-10T18:01:01Z)
• Exceptional deficiency of non-Hermitian systems: high-dimensional coalescence and dynamics [1.6741394365746018]
  We report the discovery of a generalization to the concept of exceptional deficiency (ED) The characteristics of the ED are studied using one-way coupled Hermitian and non-Hermitian lattices. The conditions of the ED are also explored for unprecedented control of localization and propagation in non-Hermitian systems.
  arXiv  Detail & Related papers  (2025-04-16T16:43:42Z)
• Topological eigenvalues braiding and quantum state transfer near a third-order exceptional point [19.317159837094202]
  We experimentally investigate the eigenvalues braiding and state transfer arising from the encirclement of exceptional points (EP) in a non-Hermitian quantum system.<n>Our findings offer insights into understanding non-Hermitian topological structures and the manipulation of quantum states through dynamic operations.
  arXiv  Detail & Related papers  (2024-12-19T11:02:49Z)
• Programmable simulation of high-order exceptional point with a trapped ion [20.656857180988926]
  We experimentally demonstrate a native programmable control to simulate a high-order non-Hermitian Hamiltonian in a multi-dimensional trapped ion system.<n>Our results pave the way for scalable quantum simulation of high-dimensional dissipative systems.
  arXiv  Detail & Related papers  (2024-12-13T01:00:22Z)
• Dynamic manifestation of exception points in a non-Hermitian continuous model with an imaginary periodic potential [0.0]
  This study focuses on exceptional points (EPs) in continuous systems rather than discrete non-Hermitian systems. The non-Hermiticity of the system stems from the local imaginary potential, which can be effectively achieved through particle loss. Our investigation sheds light on EP behaviors, potentially catalyzing further exploration of EP phenomena across a variety of quantum simulation setups.
  arXiv  Detail & Related papers  (2024-11-09T09:34:20Z)
• Topological Order in the Spectral Riemann Surfaces of Non-Hermitian Systems [44.99833362998488]
  We show topologically ordered states in the complex-valued spectra of non-Hermitian systems. These arise when the distinctive exceptional points in the energy surfaces of such models are annihilated. We illustrate the characteristics of the topologically protected states in a non-Hermitian two-band model.
  arXiv  Detail & Related papers  (2024-10-24T10:16:47Z)
• Topological transitions in quantum jump dynamics: Hidden exceptional points [45.58759752275849]
  Phenomena associated with exceptional points (EPs) and their applications have been extensively studied.<n>We consider a monitored three level system and find multiple EPs in the Lindbladian eigenvalues considered as functions of a counting field.<n>We demonstrate that these EPs signify transitions between different topological classes.
  arXiv  Detail & Related papers  (2024-08-09T18:00:02Z)
• Non-Markovian Quantum Exceptional Points [0.691134806386887]
  We propose a theoretical framework based on numerically exact descriptions of non-Markovian dynamics. We unveil pure non-Markovian EPs that are unobservable in the Markovian limit. These findings lay a theoretical foundation and open new avenues for non-Markovian reservoir engineering and non-Hermitian physics.
  arXiv  Detail & Related papers  (2024-06-26T14:01:17Z)
• Sensing of magnetic field effects in radical-pair reactions using a quantum sensor [50.591267188664666]
  Magnetic field effects (MFE) in certain chemical reactions have been well established in the last five decades. We employ elaborate and realistic models of radical-pairs, considering its coupling to the local spin environment and the sensor. For two model systems, we derive signals of MFE detectable even in the weak coupling regime between radical-pair and NV quantum sensor.
  arXiv  Detail & Related papers  (2022-09-28T12:56:15Z)
• Double exceptional points generated by the strong imaginary coupling of a non-Hermitian Hamiltonian in an optical microcavity [1.6559869843284152]
  We generate exceptional points (EPs) on two-level systems in a single microcavity by adopting the non-Hermitian coupling of a non-Hermitian Hamiltonian under the imaginary (dominant) coupling. To generate multiple EPs, multiple levels or composite physical systems have been employed with Hermitian couplings.
  arXiv  Detail & Related papers  (2022-08-14T14:36:46Z)
• Mesoscopic transport signatures of disorder-induced non-Hermitian phases [0.0]
  We investigate the impact on basic quantum transport properties of disorder-induced exceptional points (EPs) that emerge in a disorder-averaged Green's function description of two-dimensional (2D) Dirac semimetals. We find that EPs may promote the nearly vanishing conductance of a finite sample at the Dirac point to a sizable value that increases with disorder strength.
  arXiv  Detail & Related papers  (2022-01-14T19:00:01Z)
• Observation of Hermitian and Non-Hermitian Diabolic Points and Exceptional Rings in Parity-Time symmetric ZRC and RLC Dimers [62.997667081978825]
  We show how appears non-Hermitian degeneracy points in the spectrum and how they are protected against a Hermitian perturbation. This work opens a gold road for investigations on topological electrical circuits for robust transport of information at room temperature.
  arXiv  Detail & Related papers  (2020-04-17T15:51:49Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.