Squeezed states are quantum states of a harmonic oscillator in which the variance of two conjugate variables each oscillate out of phase. Ultrafast optical excitation of crystals can create squeezed phonon states, where the variance of the atomic displacements oscillates due to a sudden change in the interatomic bonding strength. With femtosecond x-ray diffraction we measure squeezing oscillations in bismuth and conclude that they are consistent with a model in which electronic excitation softens all phonon modes by a constant scaling factor.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.102.175503 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Unveiling the Mechanism of Phonon-Polariton Damping in α-MoO.
ACS Photonics
September 2024
Department of Physics, University of Oviedo, Oviedo 33006, Spain.
Phonon polaritons (PhPs), light coupled to lattice vibrations, in the highly anisotropic polar layered material molybdenum trioxide (α-MoO) are currently the focus of intense research efforts due to their extreme subwavelength field confinement, directional propagation, and unprecedented low losses. Nevertheless, prior research has primarily concentrated on exploiting the squeezing and steering capabilities of α-MoO PhPs, without inquiring much into the dominant microscopic mechanism that determines their long lifetimes, which is key for their implementation in nanophotonic applications. This study delves into the fundamental processes that govern PhP damping in α-MoO by combining calculations with scattering-type scanning near-field optical microscopy (s-SNOM) and Fourier transform infrared (FTIR) spectroscopy measurements across a broad temperature range (8-300 K).
View Article and Find Full Text PDF[Not Available].
Adv Mater
January 2025
Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
Topological bosonic systems have recently aroused intense interests in exploring exotic phenomena that have no counterparts in electronic systems. The squeezed bosonic interaction in these systems is particularly interesting, because it can modify the vacuum fluctuations of topological states, drive them into instabilities, and lead to topological parametric oscillators. However, these phenomena remain experimentally elusive because of limited nonlinearities in most existing topological bosonic systems.
View Article and Find Full Text PDFPhotonic time-crystalline behaviour mediated by phonon squeezing in TaNiSe.
Nat Commun
April 2024
Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
Photonic time crystals refer to materials whose dielectric properties are periodic in time, analogous to a photonic crystal whose dielectric properties is periodic in space. Here, we theoretically investigate photonic time-crystalline behaviour initiated by optical excitation above the electronic gap of the excitonic insulator candidate TaNiSe. We show that after electron photoexcitation, electron-phonon coupling leads to an unconventional squeezed phonon state, characterised by periodic oscillations of phonon fluctuations.
View Article and Find Full Text PDFRoom-temperature quantum optomechanics using an ultralow noise cavity.
Nature
February 2024
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
Article Synopsis
- Researchers have observed mechanical motion influenced by light at room temperature, overcoming challenges like low mechanical quality factors and noise in solid-state systems.
- They developed a phononic-engineered membrane-in-the-middle system, achieving a 700-fold reduction in cavity frequency noise and a high quality factor of 180 million through soft-clamping techniques.
- This advancement allows for improved displacement sensing and the preparation of thermal states in the oscillator, pushing the boundaries of quantum control in macroscopic solid-state resonators.
Here, a scheme for a controllable nonreciprocal phonon laser is proposed in a hybrid photonic molecule system consisting of a whispering-gallery mode (WGM) optomechanical resonator and a χ-nonlinear WGM resonator, by directionally quantum squeezing one of two coupled resonator modes. The directional quantum squeezing results in a chiral photon interaction between the resonators and a frequency shift of the squeezed resonator mode with respect to the unsqueezed bare mode. We show that the directional quantum squeezing can modify the effective optomechanical coupling in the optomechanical resonator, and analyze the impacts of driving direction and squeezing extent on the phonon laser action in detail.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!