Work

Terahertz electro-optic effect in Bi2Se3 crystals

Year: 2025

Type: article

Abstract: We report the observation of the electro-optic effect in Bi2Se3 crystals induced by an intense single-cycle terahertz pulse. The effect reveals itself as a transient change of the polarization state of a femtosecond laser pulse reflected from the crystal that is exposed to the terahertz electric field. The corresponding experimental signal follows the field with a sub-100-fs delay and can be represented as a linear combination of the terahertz electric field and its square. The linear and quadratic components are of comparable magnitude. The latter is almost independent of crystal orientation, while the former demonstrates threefold rotational symmetry in agreement with the trigonal symmetry of the crystal surface. The electro-optic effect vanishes upon phase transition to the non-topological metal state induced by indium doping and also can be quenched by a femtosecond pre-pulse. We associate this effect with surface Dirac electronic states of Bi2Se3 and discuss its possible mechanisms.

Source: Journal of Applied Physics

DOI: 10.1063/5.0246470

Authors: A. A. Melnikov, A. A. Sokolik, Yu. G. Selivanov, S. V. Chekalin

Institutions: National Research University Higher School of Economics, Institute of Spectroscopy, P.N. Lebedev Physical Institute of the Russian Academy of Sciences

Language: English

Topic: Terahertz technology and applications

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,500

Funder: Russian Science Foundation