Tunable Interactions in 2-dimensional Materials for Quantum Matter and Light

Introduction

Interactions amongst a macroscopic number of constituents lead to emergent, collective phenomena such as magnetism and superconductivity. Quantum confinement enhances interactions between electrons, leading to a wide variety of many-body quantum phases.

Atomically Thin Layered Materials

Atomically thin layered materials such as monolayer semiconductors are prime candidates to study the effect of interactions due to extreme quantum confinement. Moreover, they offer unique features such as heterostructure assembly aided by van der Waals interactions, allowing for engineered electronic properties.

Recent Discoveries

Recently, electronic transport measurements have uncovered correlated electronic phases such as Mott-insulators and superconductors in heterostructures of seemingly ordinary semiconductors such as MoSe2 and WSe2. This begs the question of whether correlated phases of optical excitations, such as excitons, can be realized in such heterostructures.

Out-of-Equilibrium Phases

In addition to being generated on demand, such out-of-equilibrium phases should have a richer phase diagram. Moreover, correlations amongst optical excitations could translate to the emission of non-classical light. Despite these attractive features, a solid-state system that exploits all the aforementioned properties is currently lacking.

Proposal Objectives

This proposal aims to realize a versatile 2D materials platform with tunable attractive and repulsive interactions amongst optical excitations and use it to create spontaneously ordered phases such as:

1. Excitonic ferromagnet
2. Dipolar crystals

We will also explore these phases for exotic light generation.

Interplay of Interactions and Geometry

Finally, we will exploit the interplay between strong interactions and the underlying geometry and topology of electronic states to hunt for elusive topological correlated phases such as fractional quantum Hall states of excitons.

Conclusion

The achievement of these objectives will uncover design principles for exotic quantum phases and enable the discovery of novel quantum matter and light – a fundamental goal of condensed matter physics.