Description: Rapid propagation of a Bloch wave packet excited by a femtosecond ultraviolet pulse

This title appears in the Scientific Report : 2016

Rapid propagation of a Bloch wave packet excited by a femtosecond ultraviolet pulse

Attosecond streaking spectroscopy of solids provides direct observation of the dynamics of electron excitation and transport through the surface. We demonstrate the crucial role of the exciting field in electron propagation and establish that the lattice scattering of the outgoing electron during th...

Personal Name(s):	Krasovskii, E. E. (Corresponding author)
	Friedrich, Christoph / Schattke, W. / Echenique, P. M.
Contributing Institute:	Quanten-Theorie der Materialien; IAS-1 JARA - HPC; JARA-HPC JARA-FIT; JARA-FIT Quanten-Theorie der Materialien; PGI-1
Published in:	Physical review / B, 94 (2016) 19, S. 195434
Imprint:	Woodbury, NY Inst. 2016
DOI:	10.1103/PhysRevB.94.195434
Document Type:	Journal Article
Research Program:	Controlling Configuration-Based Phenomena Controlling Spin-Based Phenomena
Link:	OpenAccess OpenAccess
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1103/PhysRevB.94.195434 in citations.
Please use the identifier: http://hdl.handle.net/2128/13206 in citations.

Attosecond streaking spectroscopy of solids provides direct observation of the dynamics of electron excitation and transport through the surface. We demonstrate the crucial role of the exciting field in electron propagation and establish that the lattice scattering of the outgoing electron during the optical pumping leads to the wave packet moving faster than with the group velocity and faster than the free electron. We solve the time-dependent Schrödinger equation for a model of laser-assisted photoemission, with inelastic scattering treated as electron absorption and alternatively by means of random collisions. For a weak lattice scattering, the phenomenological result that the photoelectron moves with the group velocity dE/dℏk and traverses on average the distance equal to the mean-free path is proved to hold even at very short traveling times. This offers a novel interpretation of the delay time in streaking experiment and sheds new light on tunneling in optoelectronic devices.