Geometric phase of light-induced conical intersections: adiabatic time-dependent approach

ABSTRACT

Conical intersections are degeneracies between electronic states and are very common in nature. It has been found that they can also be created both by standing or by running laser waves. The latter are called light-induced conical intersections. It is well known that conical intersections are the sources for numerous topological effects which are manifested, e.g. in the appearance of the geometric or Berry phase. In one of our former works by incorporating the diabatic-to-adiabatic transformation angle with the line-integral technique, we have calculated the Berry-phase of the light-induced conical intersections. Here, we demonstrate that by using the time-dependent adiabatic approach suggested by Berry the geometric phase of the light-induced conical intersections can also be obtained and the results are very similar to those of the time-independent calculations.

GRAPHICAL ABSTRACT

KEYWORDS:

• Born–Oppenheimer approximation
• conical intersections
• light-induced conical intersections
• geometric phase

Acknowledgments

The supercomputing service of NIIF has been used for this work. This research was supported by the EU-funded Hungarian grant EFOP-3.6.2-16-2017-00005. The authors thank Tamás Vértesi for many fruitful discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Here, we allow a very slow time-dependence of the R and θ parameters, so as to assume an implicit adiabatic time dependence of the working Floquet Hamiltonian.

2. From now on we will refer to γ as Berry, geometric or adiabatic phase.

Additional information

Funding

EU-funded Hungarian [grant number EFOP-3.6.2-16-2017-00005].