I review how methods from mesoscopic physics can be applied to describe the multiple wave scattering and complex wave dynamics in non-Hermitian PT-symmetric resonators, where an absorbing region is coupled symmetrically to an amplifying region. Scattering theory serves as a convenient tool to classify the symmetries beyond the single-channel case and leads to effective descriptions that can be formulated in the energy domain (via Hamiltonians) and in the time domain (via time evolution operators). These models can then be used to identify the mesoscopic time and energy scales that govern the spectral transition from real to complex eigenvalues. The possible presence of magneto-optical effects (a finite vector potential) in multi-channel systems leads to a variant (termed PTT' symmetry) that imposes the same spectral constraints as PT symmetry. I also provide multi-channel versions of generalized flux-conservation laws.
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http://dx.doi.org/10.1098/rsta.2012.0194 | DOI Listing |
Photodiagnosis Photodyn Ther
January 2025
Urology Department, the First Affiliated Hospital of Xinjiang Medical University. Xinjiang Clinical Reseach Center for Genitourinary System; State Key Laboratory of Patho-genesis, Prevention and Treatment of High Incidence Diseases in Central Asia. Electronic address:
(background): With the highest 5-year recurrence rate among malignancies, bladder cancer is a relatively common type of cancer that typically originates from the urothelial cells lining the bladder. Additionally, bladder cancer is one of the most financially burdensome neoplasms to medical institutions in terms of management. Hence, prompt identification and accurate handling of bladder cancer are pivotal for enhancing patient prognosis.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
School of Physical Sciences, Indian Association for the Cultivation of Science, 2A & B Raja S C Mullick Road, Kolkata 700032, INDIA, Kolkata, 700032, INDIA.
The breaking of inversion symmetry combined with spin-orbit coupling, can give rise to intrigu- ing quantum phases and collective excitations. Here, we report systematic temperature dependent Raman scattering and theoretical calculations of phonon modes across the inversion symmetry- breaking structural transitions in a quasi-one-dimensional compound (TaSe4)3I. Our investigation revealed the emergence of three additional Raman-active modes in Raman spectra of the low- temperature (LT) non-centrosymmetric (NC) structure of the material.
View Article and Find Full Text PDFJ Chem Phys
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
Vibro-polaritons are hybrid light-matter states that arise from the strong coupling between the molecular vibrational transitions and the photons in an optical cavity. Developing theoretical and computational methods to describe and predict the unique properties of vibro-polaritons is of great significance for guiding the design of new materials and experiments. Here, we present the ab initio cavity Born-Oppenheimer density functional theory (CBO-DFT) and formulate the analytic energy gradient and Hessian as well as the nuclear and photonic derivatives of dipole and polarizability within the framework of CBO-DFT to efficiently calculate the harmonic vibrational frequencies, infrared absorption, and Raman scattering spectra of vibro-polaritons as well as to explore the critical points on the cavity potential energy surface.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Univ Rennes, CNRS, IPR (Institut de Physique de Rennes)─UMR 6251, F-35000 Rennes, France.
Chloronium (HCl) is an important intermediate of Cl-chemistry in space. The accurate knowledge of its collisional properties allows a better interpretation of the corresponding observations in interstellar clouds and, therefore, a better estimation of its abundance in these environments. While the ro-vibrational spectroscopy of HCl is well-known, the studies of its collisional excitation are rather limited and these are available for the interaction with helium atoms only.
View Article and Find Full Text PDFChem Sci
December 2024
College of Science, Engineering and Environment, University of Newcastle Callaghan NSW 2308 Australia.
The inductive effect is a central concept in chemistry and is often exemplified by the p values of acetic acid derivatives. The reduction in p is canonically attributed to the reduction in the electron density of the carboxylate group through the inductive effect. However, wave functional theory calculations presented herein reveal that the charge density of the carboxylate group is not explained by the inductive effect.
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