# Control defeseance by anti-alignment in the excited state

## TL;DR

This paper predicts that in the excited state of certain molecules, strong fields induce anti-alignment due to opposite polarizability signs, challenging existing laser-control strategies.

## Contribution

It reveals a fundamental difference in polarizability effects between ground and excited states, showing anti-alignment dynamics in excited molecules under strong fields.

## Key findings

- Anti-alignment occurs in excited states of H2+ and similar molecules.
- Polarizability signs invert from ground to excited states, causing opposite alignment behavior.
- Laser control strategies effective in ground states may fail in excited states.

## Abstract

We predict anti-alignment dynamics in the excited state of H2+ or related homonuclear dimers in the presence of a strong field. This effect is a general indirect outcome of the strong transition dipole and large polarizabilities typically used to control or to induce alignment in the ground state. In the excited state, however, the polarizabilities have the opposite sign than in the ground state, generating a torque that aligns the molecule perpendicular to the field, deeming any laser-control strategy impossible.