# Quantized conductance through a dissipative atomic point contact

## TL;DR

This paper investigates how dissipation affects quantum conductance in ultracold atomic point contacts, demonstrating robust conductance plateaus despite losses and introducing a dissipative scanning gate microscopy technique.

## Contribution

It provides the first experimental and theoretical analysis of quantum conductance with particle loss in ultracold atoms, extending the Landauer-Büttiker formalism to dissipative systems.

## Key findings

- Observation of robust conductance plateaus despite dissipation
- Good agreement between experiment and extended theoretical model
- Development of a dissipative scanning gate microscope for cold atoms

## Abstract

Signatures of quantum transport are expected to quickly vanish as dissipation is introduced in a system. This dissipation can take several forms, including that of particle loss, which has the consequence that the total probability current is not conserved. Here, we study the effect of such losses at a quantum point contact (QPC) for ultracold atoms. Experimentally, dissipation is provided by a near-resonant optical tweezer whose power and detuning control the loss rates for the different internal atomic states as well as their effective Zeeman shifts. We theoretically model this situation by including losses in the Landauer-B\"uttiker formalism over a wide range of dissipative rates. We find good agreement between our measurements and our model, both featuring robust conductance plateaus. Finally, we are able to map out the atomic density by varying the position of the near-resonant tweezer inside the QPC, realizing a dissipative scanning gate microscope for cold atoms.