Enumerating low-frequency nonphononic vibrations in computer glasses

Edan Lerner, Avraham Moriel, Eran Bouchbinder

Research output: Contribution to journalArticlepeer-review

Abstract

In addition to Goldstone phonons that generically emerge in the low-frequency vibrational spectrum of any solid, crystalline or glassy, structural glasses also feature other low-frequency vibrational modes. The nature and statistical properties of these modes—often termed “excess modes”—have been the subject of decades-long investigation. Studying them, even using well-controlled computer glasses, has proven challenging due to strong spatial hybridization effects between phononic and nonphononic excitations, which hinder quantitative analyses of the nonphononic contribution D G ( ω ) to the total spectrum D ( ω ) , per frequency ω. Here, using recent advances indicating that D G ( ω ) = D ( ω ) − D D ( ω ) , where D D ( ω ) is Debye’s spectrum of phonons, we present a simple and straightforward scheme to enumerate nonphononic modes in computer glasses. Our analysis establishes that nonphononic modes in computer glasses indeed make an additive contribution to the total spectrum, including in the presence of strong hybridizations. Moreover, it cleanly reveals the universal D G ( ω ) ∼ ω 4 tail of the nonphononic spectrum, and opens the way for related analyses of experimental spectra of glasses.

Original languageEnglish
Article number014504
JournalJournal of Chemical Physics
Volume161
Issue number1
DOIs
StatePublished - 7 Jul 2024

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Enumerating low-frequency nonphononic vibrations in computer glasses'. Together they form a unique fingerprint.

Cite this