Summary
In this project, we build a solid-state quantum simulator for engineering a specific Hamiltonian. Quantum simulators are purpose-built devices with little to no need for error correction, thereby making this type of hardware less demanding than universal quantum computers. Our platform consists of exciton-polariton condensates in multiple quantum-wells sandwiched in a semiconductor Bragg stack onto which a two-dimensional lattice was imprinted. The lattice imprinting can be achieved, for example, by partial etching of the spacer with the lattice pattern followed by an overgrowth of the upper layers of the Bragg structure.
We are particularly interested in exciton-polariton condensates in a kagome lattice, where we can identify topological properties as a function of particle density. A standard optical technique allows us to quantify wavefunctions of exciton-polaritons. To do this, we construct an interferometer for measurement and use power-dependent photoluminescence to identify quantum phases in the kagome lattice.
Our goal is to advance the measurement of topological parameters and knowledge of condensed matter physics in engineered exciton-polariton simulators. This will serve to elucidate quantum phases in a controlled manner and bring us closer to a quantum simulator capable of delivering meaningful insights into quantum materials and optimization.

Figure 1. (top) A hexagonal lattice of micro-cavities formed in a Bragg stack structure with a spacer (white layer) sandwiching multiple quantum wells (red layers). (bottom) Bandstructures of exciton-polaritons in a two-dimensional kagome lattice. As the pump power changes, exciton-polaritons undergo phase transition to form coherent states: below threshold (a) P/Pth ~ 0.04, near threshold (b) P/Pth ~ 1, and above threshold (c) P/Pth ~ 2, where Pth is the threshold pump power.
Related Content

Functionalized Nanodiamonds for Sensing Biochemical Processes
Summary Chemotherapy is limited by the failure to clinically monitor the efficacy of the treatment in real-time, which results in suboptimal chemotherapy being given for a prolonged period. Predicting the outcome of chemotherapy immediately after drug administration can increase diagnostic accuracy, efficacy outcomes, and successful treatment. Quantum nanodiamond sensors can be used as optical sensors […]
August 31, 2022

Coherent magnon generation, magnon condensation, and quantum spin liquids via spin pumping in 2D magnets
Summary Developing hybrid quantum systems is essential to harnessing the complementary advantages of different quantum technology platforms. This necessitates the successful transfer of quantum information between platforms, which can be achieved, e.g., by harnessing magnons, or spin wave excitations, in magnetic materials. Decoherence due to uncontrolled coupling of qubits to the environment remains a fundamental […]
February 1, 2023

Mesoscopic systems as coherent control elements
Summary Mesoscopic systems provide a new tool for quantum systems design. In particular, they are enabling of robust quantum control. Here “mesoscopic system” refers to a connected network where each element, if studied alone, would be a quantum bit. The network is too big to be treated fully quantum mechanically. We do not have individual […]
September 1, 2016

Towards large area, resonant quantum tunneling diodes by continuous Langmuir transfer of exfoliated 2D materials
Summary Atomically thin 2D materials constitute promising building blocks for quantum devices due to their exotic, layer-dependent electronic properties. The ability to stack these materials in alternating layers enables heterostructures to be built in almost limitless combinations and over small enough length scales to observe quantum phenomena. So far though, practical implementation of devices based […]
April 1, 2020