Dipolar fermions in a multilayer geometry

TL;DR

This paper explores the phases of multilayer dipolar fermions at zero temperature, revealing how the stripe phase evolves with the number of layers and identifying a collapse transition in the infinite-layer limit.

Contribution

It provides a comprehensive analysis of density instabilities and stripe phases in multilayer dipolar fermions, including an analytic expression for interlayer effects and the transition to collapse.

Findings

Stripe phase exists over a wider angle range with more layers.

The stripe phase can span all angles when interlayer distance is small.

Infinite layers lead to a collapse of the system.

Abstract

We investigate the behavior of identical dipolar fermions with aligned dipole moments in two-dimensional multilayers at zero temperature. We consider density instabilities that are driven by the attractive part of the dipolar interaction and, for the case of bilayers, we elucidate the properties of the stripe phase recently predicted to exist in this interaction regime. When the number of layers is increased, we find that this "attractive" stripe phase exists for an increasingly larger range of dipole angles, and if the interlayer distance is sufficiently small, the stripe phase eventually spans the full range of angles, including the situation where the dipole moments are aligned perpendicular to the planes. In the limit of an infinite number of layers, we derive an analytic expression for the interlayer effects in the density-density response function and, using this result, we find that the stripe phase is replaced by a collapse of the dipolar system.