# Anisotropic blockade using pendular Rydberg butterfly molecules

## TL;DR

This paper proposes an experiment demonstrating a novel anisotropic blockade mechanism in ultracold dipolar gases of butterfly Rydberg molecules, highlighting tunable long-range interactions and their dependence on molecular orientation.

## Contribution

It introduces a new blockade mechanism based on anisotropic interactions in butterfly Rydberg molecules, with tunability via external fields and molecular orientation.

## Key findings

- Interaction causes state shifts preventing simultaneous excitation.
- Molecular density depends on trap axis and field angle.
- Wide tunability of interactions using available Rydberg states.

## Abstract

We propose an experiment to demonstrate a novel blockade mechanism caused by long-range anisotropic interactions in an ultracold dipolar gas composed of the recently observed "butterfly" Rydberg molecules. At the blockade radius, the strong intermolecular interaction between two adjacent molecules shifts their molecular states out of resonance with the photoassociation laser, preventing their simultaneous excitation. When the molecules are prepared in a quasi-one-dimensional (Q1D) trap, the interaction's strength can be tuned via a weak external field. The molecular density thus depends strongly on the angle between the trap axis and the field. The available Rydberg and molecular states provide a wide range of tunability.