Optical transitions between entangled electron–phonon states in silicon

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F10974938%3A_____%2F25%3A25_88_26" target="_blank" >RIV/10974938:_____/25:25_88_26 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1063/5.0288893" target="_blank" >https://doi.org/10.1063/5.0288893</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0288893" target="_blank" >10.1063/5.0288893</a>

Result language

angličtina

Original language name

Optical transitions between entangled electron–phonon states in silicon

Original language description

Silicon crystallizes in the diamond structure with two atoms per unit cell and supports three optical phonon modes. However, due to the centrosymmetric nature of the lattice, these modes do not induce a net dipole moment and are therefore inactive in infrared absorption. Even in polar semiconductors, where optical phonons can be IR-active, conventional techniques such as infrared absorption and Raman spectroscopy are restricted to probing phonons at the Brillouin zone center (Gamma-point). In this work, we demonstrate that time- and spectrally resolved pump-probe ellipsometry enables access to the coherent response of electron-phonon coupled states involving both valence and conduction bands. Following two-photon absorption induced by the femtosecond pump pulse, the electronic excitation relaxes and drives the generation of coherent longitudinal optical phonons along the X-direction of the Brillouin zone, followed by optical transitions of entangled electron-phonon states along the Lambda-direction. This process results in a transient, strongly correlated electron-phonon state that persists for up to approximate to 300 fs. Within this coherent time window, the silicon crystal exhibits optical resonances at electronic transition energies modulated by quantized phonon contributions. Finally, we detect further sidebands in the ellipsometric spectrum, which are 81 meV apart and assign these to two-phonon-assisted electronic transitions. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/EF16_019%2F0000789" target="_blank" >EF16_019/0000789: Advanced research using high intensity laser produced photons and particles</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Applied Physics Letters

ISSN

0003-6951

e-ISSN

1077-3118

Volume of the periodical

127

Issue of the periodical within the volume

14

Country of publishing house

US - UNITED STATES

Number of pages

6

Pages from-to

141102 (1-6-)

UT code for WoS article

001590133000001

EID of the result in the Scopus database

2-s2.0-105018062721