Most physicists are familiar with how nonrelativistic quantum mechanics governs the behavior of particles in a Coulomb potential or a simple harmonic oscillator potential. But what happens when the particles become highly relativistic? Such questions used to lie mainly in the domain of high and intermediate energy physics. With the discovery that…

Recent theoretical and experimental progress in continuously monitored quantum systems has permitted the real-time tracking of the quantum state during the measurement process. I will discuss (1) how to predict the most likely path between two boundary conditions in time, (2) the probability distribution of entanglement created by the…

When we first learn the physics of solids, we are taught the theory of perfect crystals. Only later do we learn that in the real world, all solids are imperfect. The perfect crystal is invaluable because we can describe real solids by perturbing around this extreme limit by adding defects. But such an approach fails to describe a glass,…

Out-of-time-order correlation functions are of theoretical interest for diagnosing the scrambling of quantum information in black holes and strongly interacting quantum systems generally. I will describe a general protocol for measuring them which requires an echo-type sequence in which the sign of a many-body Hamiltonian is reversed. I will…

Abstract not available.

Research in quantum computing is a still-growing field, fueled by interest in both it’s powerful applications and connection to fundamental science.  Qubits, the building blocks of future quantum computers, must both manipulate and protect the quantum information they hold – a task fraught with challenges.  In this talk, I will describe some of…

The delafossites are a series of layered compounds with triangular lattices similar to that of NaCoO2 but with a different stacking sequence along the c axis. They are host to intriguing magnetic insulators and semimetals, as well as metals such as PdCoO2, PtCoO2, PdCrO2 and PdRhO2. The properties of these metals are remarkable. Although they…

Abstract: Recent experiments have provided mounting evidence for the existence of Majorana bound states (MBSs) in condensed-matter systems. Until the long-term goal of braiding MBSs is achieved, one is prompted to ask: what is the next step in the study of topological superconductivity and MBSs? In my talk I will discuss two topics relating to…

Although hydrodynamics is believed to be a universal limit for many interacting quantum systems, observing this regime is hard in ordinary metals. Thanks to recent developments in materials physics, graphene is a material where we should hope to observe multiple interesting hydrodynamic regimes. I will first discuss the indirect observation of…

Lindbladians, one of the simplest extensions of Hamiltonian-based quantum mechanics, are used to describe “drainage” (i.e., decay) and decoherence of a quantum system induced by the system's environment. While traditionally viewed as detrimental to fragile quantum properties, a tunable environment offers the ability to drive the system toward…

The coherent optical manipulation of solids is emerging as a promising way to engineer novel quantum states of matter. The strong time-periodic potential of intense laser light was predicted to generate hybrid photon–electron states named Floquet–Bloch states. In this talk, I will report on first experimental observation of these states in…

Models for metallic anti-ferromagnets map to the dissipative XY model as do XY ferromagnets, the superconductor-insulator transition, and the model forloop-current order in Cuprates. The spectral function of the quantum-critical fuctuations for this model in 2D for a range of parameters is determined by topological defects - instantons and 2D…

A quantum many-body system, prepared initially in a state with low entanglement, will entangle distant regions dynamically. How does this happen? I will discuss entanglement entropy growth for quantum systems subject to random unitary dynamics — i.e. Hamiltonian evolution with time-dependent noise, or a random quantum circuit. I will show how…

Spatial symmetries in crystals are distinguished by whether they preserve the spatial origin. I will show how this basic geometric property gives rise to a new topology in band insulators, which we propose (and subsequently discover) to lie in the large-gap insulators: KHgX (X=As,Sb,Bi). These insulators are described by generalized symmetries…

One of the distinctive characteristics of strongly interacting and correlated quantum systems is the non-trivial interplay between low- and high-energy degrees of freedom. The origin of this interplay lies in the electron-electron and electron-boson interactions, which spread the optical spectral weight over a wide energy range. To address this…

Complex quantum many-body systems are ubiquitous in nature, yet their behaviour often remains very challenging to predict with analytical or numerical calculations - especially when it comes to dynamics. However, using ultracold atoms in optical lattices it is possible to create precisely tunable, yet very accessible complex systems, which can be…

About ten years ago, a new electronic material appeared – notable not only for its ease of preparation and theoretical simplicity, but also by its promise for future electronic devices. Single monatomic sheets of carbon, known as graphene, are described as weakly interacting massless Dirac fermions and in many ways, are a textbook system to test…