Electronic excitations in hcp {sup 4}He at 61.5 MPa and 4.3 K studied by inelastic x-ray scattering spectroscopy

Journal Article · Mon Mar 27 04:00:00 EST 1995 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.74.2535· OSTI ID:27866

Schell, N; Simmons, R O; Kaprolat, A; Schuelke, W; Burkel, E ^[1]

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1. Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf e.V., D-01314 Dresden (Germany)

The dynamic structure factor {ital S}({ital {rvec q}},{omega}) of electrons in solid {sup 4}He was measured with 1.6 eV energy resolution by means of inelastic scattering of synchrotron x rays from a hcp single crystal for {ital {rvec q}} along the {ital c} axis and for {ital q}=0.45, 0.97, and 1.24 a.u. The hcp crystal was grown {ital in} {ital situ} at 61.5 MPa and 4.3 K. A {ital q}-independent energy loss peak at 21.9{plus_minus}0.3 eV could unambiguously be identified. These signals are the first directly measured electronic excitations in solid helium. They are discussed in terms of excitonic excitations.

• Research Organization: University of Illinois
• DOE Contract Number: FG02-91ER45439
• OSTI ID: 27866
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 13 Vol. 74; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRONIC STRUCTURE
HCP LATTICES
HELIUM 4
INELASTIC SCATTERING
PRESSURE DEPENDENCE
SOLIDS
STRUCTURE FACTORS
SYNCHROTRON RADIATION
X-RAY SPECTRA