Prof Sid Parameswaran discusses how quantum condensed matter physics has been revolutionized by “moiré materials”, made by stacking individual atomically thin layers such as graphene with a relative twist/offset between layers. The world of quantum condensed matter physics has recently been revolutionized by the advent of “moiré materials”, made by stacking individual atomically thin layers such as graphene (a two dimensional form of carbon) with a relative twist or offset between the layers. Electrons see a long-wavelength potential as they scatter from the positive ions in the different layers, leading to the formation of a new type of two-dimensional electron gas. In certain circumstances, the resulting electronic states are analogous to the Landau levels that lie at the heart of the quantum Hall effect, but form without an external magnetic field. This has led to the experimental realisation of the long-sought “fractional Chern insulator” state of matter, and has triggered an ongoing worldwide effort to explore other effects of the interplay of topology and interactions in this new setting. I’ll discuss the origins of the moiré phenomenon, and survey the exciting developments in the field, including some with links to Oxford.

While it was originally believed that only bosons and fermions were allowed by quantum mechanics, in fact, when objects are restricted to move on a two-dimensional plane, new types of particles called "anyons" can emerge. For much of the last century it was believed that the only types of particles allowed by quantum mechanics are bosons (such as photons, phonons, pions, Higgs, etc.) and fermions (such as electrons, muons, quarks, etc.). This rule of only two particle types turns out to be a reflection of the dimensionality of space. When objects are restricted to move on a two-dimensional plane, new types of particles, called "anyons" can emerge. While originally just a theoretical fantasy, such particles have recently been observed in several different types of experiments. I will discuss the history of this field, why it is viewed as important, and recent progress.

Prof Shivaji Sondhi explains how topology is applied to understanding properties of condensed matter systems, providing an introduction to topics including defects & solitons, the quantum Hall effect, and topological insulators. The mathematics of topology has been applied with increasing success to understanding the properties of condensed matter systems. Indeed, it is fair to say that over the past couple of decades, it has revolutionized our understanding of what forms of order are possible in quantum matter. In this talk, I will provide a brief, pedagogical introduction to some of the most well-known applications of topological ideas. These will include topics such as defects & solitons, the quantum Hall effect, and topological insulators.

Professor Prateek Agrawal discusses the ongoing crisis in cosmology regarding the measurement of the Hubble parameter by two separate probes in this Morning of Theoretical Physics talk from 9th November, 2024 Professor Prateek Agrawal discusses the Hubble tension. Cosmology has matured into a precision science over the last couple of decades. We are now in a position to test cosmological models to percent level precision, and cracks in our understanding of the universe have emerged. I will show how the measurement of the Hubble parameter by two separate probes has become an ongoing crisis in cosmology, and discuss some of the proposed solutions.

Professor Edward Hardy discusses how the network of cosmic strings that occurs in some theories of the early Universe evolves and emits gravitational waves in this Morning of Theoretical Physics talk from 9th November, 2024. Professor Edward Hardy discusses cosmic strings and gravitational waves from the early Universe. Cosmic strings are one-dimensional objects that often arise if a symmetry is spontaneously broken, as occurs in the early Universe in many theories of physics beyond the standard model. I will describe how the resulting network of strings evolves and in the process emits gravitational waves. These gravitational waves might be detectable in spectacularly precise searches today, and if discovered could give us information about physics at extremely high energies, far beyond any that could be explored directly e.g. in particle colliders.

Prof Alexander Mietke discusses recent findings in this field that have linked chirality in living systems to the formation of a left-right body axis in organisms and to a new kind of elasticity that is found in crystals formed by starfish embryos. Chirality describes objects and features that are distinct from their mirror image, a property that can be found in many biological systems ranging from spiral patterns of seashells over helical swimming paths of sperm cells to the shape of our hands and feet. This is rather surprising, given that most organisms develop from a single, round cell which shows no obvious signs of chirality. The physics of chirality in biological systems is a research area within the modern field of living matter that aims to identify the physical principals that underlie how chirality emerges during organism development and how the chiral nature of biological materials contributes to their highly unconventional mechanical properties

Dr Adrien Hallou presents a new methodology called 'spatial mechano-transcriptomics', which allows the simultaneous measurement of the mechanical and transcriptional states of cells in a multicellular tissue at single cell resolution. Over the last 10 years, advances in microscopy and genome sequencing have revolutionised our understanding of how molecular programmes contained in the genome control cellular behaviours such as cell division, differentiation or death, and how these behaviours are influenced by biochemical and mechanical signals from the cell environment. In this talk, I will present a new methodology called 'spatial mechano-transcriptomics', which allows the simultaneous measurement of the mechanical and transcriptional states of cells in a multicellular tissue at single cell resolution. This new framework provides a generic scheme for exploring the interplay of biomolecular and mechanical cues in tissues in a variety of contexts, such as embryonic development, tissue homeostasis and regeneration, but also in diseases such as cancer.

Professor Julia Yeomans describes how mechanical models are being extended to incorporate the unique properties of living systems Epithelial tissues cover the outer surfaces of the body and line the body’s internal cavities. The motion of epithelial cells is key to many life processes: turnover of skin cells, embryogenesis, the spread of cancer and wound healing. Much remains to be understood about the ways in which cells interact and move together. I will describe how mechanical models are being extended to incorporate the unique properties of living systems.

In this talk, Benedikt Placke introduces QEC and explains how the unique interplay between the classical and the quantum world enables us to efficiently correct errors effecting such systems. Quantum computing is a new model of computation that holds the promise of significantly improved performance over classical computing for some problems of interest. However, by its very nature quantum computers are sensitive to disturbance by external noise, most likely necessitating the use quantum error correction (QEC) for useful application. Furthermore, Benedikt Placke comments on the deep connection between QEC and questions in condensed matter physics.

In this talk Alessio Lerose discusses the seminal idea of simulating Nature via a controllable quantum system rather than a classical computer. He discusses recent advances that brought us closer to the ultimate goal of a universal quantum simulator. Since their birth computers proved invaluable tools for physics research. Quantum mechanics, however, fundamentally challenges the possibility for computers to simulate dynamics of matter. In fact, solving the quantum-mechanical law of motion requires to account for contributions of all possible joint configuration histories of all constituents of a system: a task that quickly becomes unbearable for any imaginable computer. Our understanding of complex phenomena involving important quantum-mechanical effects, such as chemical reactions, high-temperature superconducting materials, as well as the primordial universe evolution, is obstructed by this fundamental technological limitation.

Jasmine Brewer covers recent progress on studying the properties of the quark-gluon plasma, and describe how we can capitalize on lessons learned from high-energy physics to provide new insights on this novel material. Quarks and gluons are the fundamental constituents of all matter in the universe, but they have the unique property that they are always confined inside hadrons. The only situation in which quarks and gluons are deconfined is in extremely high-energy collisions of heavy nuclei, where the temperature is so high that nuclei “melt” into a new phase of matter called the quark-gluon plasma. This exotic state of matter provides a gateway to study the rich many-body physics of free quarks and gluons, including their rapid thermalization to form the most perfect liquid ever observed.