Optical conductivity of rattling phonons in type-I clathrateBa8Ga16Ge30
نویسندگان
چکیده
منابع مشابه
NMR relaxation and rattling phonons in the type-I Ba8Ga16Sn30 clathrate
Atomic motion of guest atoms inside semiconducting clathrate cages is considered an important source for glasslike thermal behavior. 69Ga and 71Ga nuclear magnetic resonance studies on type I Ba8Ga16Sn30 show a clear low-temperature relaxation peak attributed to the influence of Ba rattling dynamics on the framework-atom resonance, with a quadrupolar relaxation mechanism as the leading contribu...
متن کاملTheoretical study of NMR relaxation due to rattling phonons
We calculate the NMR relaxation rate due to quadrupolar coupling of the nucleus to a local, strongly anharmonic phonon mode. As a model potential for a “rattling” motion we consider a square-well potential. We calculate the free phonon Green’s function analytically and derive the low and high temperature limits of the NMR relaxation rate. It is shown that the temperature dependence of the NMR r...
متن کاملOptical conductivity spectral anomalies in the off-center rattling system β-Ba8Ga16Sn30.
We present optical conductivity studies of the type-I clathrate Ba8Ga16Sn30, using a terahertz time-domain spectrometer (0.3-3.0 THz). The lowest-lying spectral peak at 0.72 THz due to the Ba(2) ion's off-center vibration in the oversized cage shows a drastic and anomalous temperature dependence. Below about 100 K, the single broad peak splits into two subpeaks, and with further lowering of the...
متن کاملEffects of optical and surface polar phonons on the optical conductivity of doped graphene
Using the Kubo linear response formalism, we study the effects of intrinsic graphene optical and surface polar phonons (SPPs) on the optical conductivity of doped graphene. We find that inelastic electron-phonon scattering contributes significantly to the phonon-assisted absorption in the optical gap. At room temperature, this midgap absorption can be as large as 20–25% of the universal ac cond...
متن کاملNew type of optical bistability in polymers mediated by phonons.
A new type of optical bistability mediated by pho~ion and virtual exciton coupling is suggested for polymers. Numerical results with parameters pertaining to polydiacetylene-toluene-sulfonate are given as an illustration. The stability of the steady-state solution is examined, and the physical mechanism responsible for the bistability is discussed. 1988 PACS numbers. 42.65.-k, 42.65.pc, 36.20.-...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review B
سال: 2009
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.79.212301