# Numerical attoclock on atomic and molecular hydrogen

## TL;DR

This paper presents a numerical and semi-classical analysis of the attoclock technique on atomic and molecular hydrogen, revealing the influence of molecular orientation and two-center interference on measurement accuracy.

## Contribution

It compares numerical solutions and semi-classical models of the attoclock, and investigates molecular orientation effects and interference phenomena in hydrogen and neon dimer.

## Key findings

- Numerical and semi-classical approaches agree on key physics.
- Molecular orientation significantly affects the attoclock angular peak.
- Two-center interference influences the measurement in molecules.

## Abstract

Numerical attoclock is a theoretical model of attosecond angular streaking driven by a very short, nearly a single oscillation, circularly polarized laser pulse. The reading of such an attoclock is readily obtained from a numerical solution of the time-dependent Schr\"odinger equation as well as a semi-classical trajectory simulation. By making comparison of the two approaches, we highlight the essential physics behind the attoclock measurements. In addition, we analyze the predictions of the Keldysh-Rutherford model of the attoclock [Phys. Rev. Lett. 121, 123201 (2018)]. In molecular hydrogen, we highlight a strong dependence of the width of the attoclock angular peak on the molecular orientation and attribute it to the two-center electron interference. This effect is further exemplified in the weakly bound neon dimer.