Directly Observing Squeezed Phonon States with Femtosecond X-Ray Diffraction

Journal Article · Fri May 01 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.102.175503· OSTI ID:21316671

Johnson, S L; Beaud, P; Vorobeva, E; Ingold, G ^[1]; Milne, C J ^[2]; Murray, E D ^[3]; Fahy, S ^[4]

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1. Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)
2. Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland)
3. Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)
4. Tyndall National Institute and Department of Physics, University College, Cork (Ireland)

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.

• OSTI ID: 21316671
• Journal Information: Physical Review Letters, Vol. 102, Issue 17; Other Information: DOI: 10.1103/PhysRevLett.102.175503; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ATOMIC DISPLACEMENTS
BISMUTH
CRYSTALS
EXCITATION
EXCITED STATES
HARMONIC OSCILLATORS
OSCILLATIONS
PHONONS
X-RAY DIFFRACTION