The creation, understanding, and tuning of novel electronic and magnetic phases of solids constitutes one of the fundamental endeavours of material science and condensed-matter research. In this context, synthetic quantum materials based on lattices of strongly correlated electrons have been shown to host many exotic quantum phases of matter (such as high-temperature superconductivity or new magnetic states) when their mutual Coulomb interaction is similar or larger than their kinetic energy, with the resulting phase depending on a delicate balance between these two energy scales. The most famous theoretical model to understand and explore lattices of strongly interacting particles is the extended Hubbard model, which in its simplest form consists of a kinetic term defined by the nearest-neighbor hopping parameter (t1), and the on-site (U) and long-range (V) Coulomb repulsion. In the Hubbard picture, strong electronic correlations emerge for U>V>t, giving rise to very rich electronic and magnetic phase diagrams [1].

Despite its simplicity, the extended Hubbard model is non-trivial to solve in two or higher dimensions [1], and a wide range of techniques have been used [2,3]. Hence, experimental implementations of strongly correlated electron lattices have attracted a lot of attention as potential simulators of the Hubbard model. Such synthetic quantum materials can provide new insights into regimes not accessible by the current theoretical approaches and can guide the quest for novel exotic and technologically relevant phases of matter. A crucial requirement in a synthetic quantum material for its exploitation as a simulator of the Hubbard model is the in-situ tunability of the system parameters, which represents an experimental challenge in conventional solid-state quantum materials due to their limited range of parameter control. In this scenario, the rise of moiré heterostructures based on two-dimensional (2D) van der Waals (vdW) materials constitutes arguably one of the biggest and most exciting opportunities in the creation and manipulation of synthetic quantum materials [4-12]. Moiré materials provide an unprecedented ability to create Hubbard lattices with highly tunable length scales in the 1 – 100 nm range at temperatures corresponding to a small fraction of the exchange coupling (J) between neighbouring spins, which allow the exploration of regimes that complement those found in optical lattices and that have previously been unobtainable in ‘conventional’ materials. However, to unlock the true potential of synthetic moiré materials and navigate their phase diagrams at will, a new (still missing) functionality needs to be added: a wide-ranging in-situ tunability of the moiré lattice periodicity and geometry.

This experimental PhD project aims to pioneer the exploitation of controlled strain of moiré materials at cryogenic temperatures as a tuning knob to manipulate in-situ their lattice geometry and their emergent quantum correlated electronic, magnetic, and excitonic phases. We will optically probe the emergent quantum phase diagrams as the moiré lattice geometry is continuously tuned. Our unprecedented ability to in-situ tune and readout the energy scales of moiré materials with reconfigurable lattice geometries at cryogenic temperatures will guide the quest for novel exotic and technologically relevant phases of matter.