Optical anisotropy induced by cesium adsorption on the As-rich c(2X8) reconstruction of GaAs(001)
|Title||Optical anisotropy induced by cesium adsorption on the As-rich c(2X8) reconstruction of GaAs(001)|
|Publication Type||Palaiseau Article|
|Author Address|| |
Hogan, C (Reprint Author), Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Univ Roma Tor Vergata, INFM, I-00133 Rome, Italy. Ecole Polytech, Phys Mat Condensee Lab, F-91128 Palaiseau, France. Novosibirsk State Univ, Inst Semicond Phys, Novosibirsk 630090, Russia. Ecole Polytech, Solides Irradies Lab, CEA, CNRS,UMR 7642, F-91128 Palaiseau, France. Univ Milan, Dipartimento Fis, I-20122 Milan, Italy. Univ Milan, INFM, I-20122 Milan, Italy.
|Hogan, C, Paget, D, Tereshchenko, OE, Reining, L, Onida, G|
|Publisher||AMERICAN PHYSICAL SOC|
|Year of Publication||2004|
|Journal||Phys. Rev. B|
|Type of Work||Article|
Upon adsorption of Cs, the As-rich c(2 X 8)/(2 X 4) reconstruction of GaAs(001) is found to exhibit an intense negative signal between 3 eV and 5 eV in the reflectance anisotropy spectrum. This signal has a universal character in that similar features also appear on the Ga-rich surface. The mechanism of this signal is interpreted using ab initio calculations of Cs adsorption at As and Ga sites of the As-rich surface. The calculations succeed in explaining the universality of the signal. In the vicinity of the E-0' bulk critical point at 4.5 eV, the signal arises from perturbation of bulk states terminating at the surface. At lower energies, the signal arises from the creation of new surface resonances induced by the Cs adatom.