We study collective excitations in a helical electron liquid on a surface of three-dimensional topological insulator. Electron in helical liquid obeys Dirac-like equation for massless particles and direction of its spin is strictly determined by its momentum. Due to this spin-momentum locking, collective excitations in the system manifest themselves as coupled charge- and spin-density waves. We develop quantum field-theoretical description of spin-plasmons in helical liquid and study their properties and internal structure. Value of spin polarization arising in the system with excited spin-plasmons is calculated. We also consider the scattering of spin-plasmons on magnetic and nonmagnetic impurities and external potentials, and show that the scattering occurs mainly into two side lobes. Analogies with Dirac electron gas in graphene are discussed.PACS: 73.20.Mf; 73.22.Lp; 75.25.Dk.
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http://dx.doi.org/10.1186/1556-276X-7-163 | DOI Listing |
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January 2025
Central Research Institute, BOE Technology Group Co. Ltd, Beijing, 100176, China.
For quantum-dot light-emitting diodes (QLED), electrical aging commonly introduces collective aging sources across all layers, making it difficult to isolate the impact of each layer on electroluminescence (EL) degradation. In this work, a layer-selective aging method using active photoexcitation is proposed, in which the photoexcitation wavelength is used to selectively target specific layers for exciton generation, and an electrical bias is applied to induce photocurrent and create charges. An iterative aging-sampling (A-S) procedure is used to link aging conditions to EL degradation.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Nuclear, Plasma, and Radiological Engineering, The Grainger College of Engineering, University of Illinois Urbana-Champaign, Champaign, IL, USA.
Doped semiconductors can exhibit metallic-like properties ranging from superconductivity to tunable localized surface plasmon resonances. Diamond is a wide-bandgap semiconductor that is rendered electronically active by incorporating a hole dopant, boron. While the effects of boron doping on the electronic band structure of diamond are well-studied, any link between charge carriers and plasmons has never been shown.
View Article and Find Full Text PDFCommun Phys
January 2025
Accelerator Laboratory, Department of Physics, University of Jyväskylä, Jyväskylä, Finland.
Atomic nuclei serve as prime laboratories for investigations of complex quantum phenomena, where minor nucleon rearrangements cause significant structural changes. Pb is the heaviest known neutron-deficient Pb isotope that can exhibit three distinct shapes: prolate, oblate, and spherical, with nearly degenerate excitation energies. Here we report on the combined results from three state-of-the-art measurements to directly observe these deformations in Pb.
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 PDFCurr Biol
December 2024
Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232, USA; Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address:
Human and non-human primate studies clearly implicate the dorsolateral prefrontal cortex (dlPFC) as critical for advanced cognitive functions. It is thought that intracortical synaptic architectures within the dlPFC are the integral neurobiological substrate that gives rise to these processes. In the prevailing model, each cortical column makes up one fundamental processing unit composed of dense intrinsic connectivity, conceptualized as the "canonical" cortical microcircuit.
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