ZhETF, Vol. 126,
p. 979 (October 2004)
(English translation - JETP,
Vol. 99, No. 4,
available online at www.springer.com
COLLECTIVE EXCITATIONS IN EXCITON CRYSTAL
Kulakovskii D.V., Lozovik Yu.E., Chaplik A.V.
Received: May 19, 2004
PACS: 71.35.Lk, 73.20.Mf
Crystal phase of indirect excitons formed by spatially separated electrons and holes in coupled quantum wells is analyzed. The collective mode spectrum of the exciton crystal at zero and nonzero magnetic fields is found. The spectrum consists of two optical and two acoustical modes (transverse and longitudinal in each case). We also study changes of the dipole crystal collective excitations at the transition exciton crystal-electron-hole plasma.