Harmonic lattice behavior of two-dimensional colloidal crystals.
Using positional data from videomicroscopy and applying the equipartition theorem for harmonic Hamiltonians, we determine the wave-vector-dependent normal mode spring constants of a two-dimensional colloidal model crystal and compare the measured band structure to predictions of the harmonic lattice theory. We find good agreement for both the transversal and the longitudinal modes. For q-->0, the measured spring constants are consistent with the elastic moduli of the crystal.
Keim
P
P
Fachbereich Physik, Universität Konstanz, P.O.B. 5560, 78457 Konstanz, Germany.
Maret
G
G
Herz
U
U
von Grünberg
H H
HH