One-step theory of attosecond photoelectron spectroscopy of solid

Datum

04.04.2023

Zeit

11:00 - 12:00

Sprecher

Dr. Eugene Krasovskii

Zugehörigkeit

University of the Basque Country & Donostia International Physics Center (DIPC)

Sprache

en

Hauptthema

Materialien

Host

Grit Rötzer

Beschreibung

The energy-angular distribution of photoelectrons is the main source of experimental information about the electronic structure of the solids. Recently, also temporal parameters have become amenable to experimental investigation—namely, the time the electron needs to leave the crystal, which is the subject of time-resolved attosecond spectroscopy [1]. The talk considers theoretical approaches to the interpretation of the chronoscopic information obtained with the attosecond laser streaking technique. In particular, a straightforward application of the time-dependent Schrödinger equation is compared to a stationary-state method, which unites the one-step theory of photoemission with the Eisenbud-Wigner-Smith formalism for scattering delay [2]. An ab initio realization of the latter method in terms of augmented plane waves [3] will be presented and its application to real solids, namely to photoemission from Mg(0001) and electron transmission through graphene. For a microscopic one-dimensional model of the streaking experiment, the effect of the interaction of the outgoing photoelectron with the crystal lattice at short travel times is analyzed, and a curious observation is made that in the presence of the exciting field the photoelectron wave packet may move faster than with the group velocity [4]. Another counterintuitive phenomenon is a manifestation of the Hartman effect [5] in electron transmission through graphene: in the forbidden gap the electron wave packet moves faster than in the conducting band. [1] R. Pazourek, S. Nagele, and J. Burgdörfer, Attosecond chronoscopy of photoemission, Rev. Mod. Phys. 87, 765–802 (2015). [2] R. O. Kuzian and E. E. Krasovskii, One-step theory of photoelectron escape time: Attosecond spectroscopy of Mg(0001), Phys. Rev. B 102, 115116 (2020). [3] E. E. Krasovskii, Augmented-plane-wave approach to scattering of Bloch electrons by an interface, Phys. Rev. B 70, 245322 (2004). [4] E. E. Krasovskii, C. Friedrich, W. Schattke, and P. M. Echenique, Rapid propagation of a Bloch wave packet excited by a femtosecond ultraviolet pulse, Phys. Rev. B 94, 195434 (2016). [5] T. E. Hartman, Tunneling of a Wave Packet, J. Appl. Phys. 33, 3427–3433 (1962).

Links

• Seminars at the IFW

Letztmalig verändert: 04.04.2023, 07:38:52