# Ultrafast time-scale Berry-phase gates of atomic clock states

## TL;DR

This paper demonstrates ultrafast, pico-second scale Berry-phase gates for atomic clock states using chirped laser pulses, enabling faster qubit control with robustness against noise, which advances quantum computation speed.

## Contribution

The paper introduces a novel ultrafast Berry-phase gate method for atomic clock states using chirped laser pulses, achieving picosecond control and robustness against laser noise.

## Key findings

- Successfully implemented pico-second Berry-phase gates with rubidium atoms.
- Achieved operational robustness against laser parametric noises.
- Demonstrated ultrafast control surpassing traditional microwave or Raman methods.

## Abstract

Extremely fast qubit controls can greatly reduce the calculation time in quantum computation, and potentially resolve the finite-time decoherence issues in many physical systems. Here, we propose and experimentally demonstrate pico-second time-scale controls of atomic clock state qubits, using Berry-phase gates implemented with a pair of chirped laser pulses. While conventional methods of microwave or Raman transitions do not allow atomic qubit controls within a time faster than the hyperfine free evolution period, our approach of ultrafast Berry-phase gates accomplishes fast clock-state operations. We also achieves operational robustness against laser parametric noises, since geometric phases are determined by adiabatic evolution pathway only, without being affected by any dynamic details. The experimental implementation is conducted with two linearly polarized, chirped ultrafast optical pulses, interacting with five single rubidium atoms in an array of optical tweezer dipole traps, to demonstrate the proposed ultrafast clock-state gates and their operational robustness.