Moiré is Different: New Twists in the Tale of Strong Correlations

I will give an overview of how advances in engineering twisted two-dimensional materials with a “moiré superlattice” have revealed a rich playground for investigations into strongly-correlated electronic matter. I’ll introduce the theories deployed to explain some of the experimental puzzles that arise and give a personal view on the most promising lines of future work. Along the way, I will illustrate how some of these ideas echo historic themes in condensed matter physics, including Martin Gutzwiller’s visionary ideas on the many-body problem, and mention how they tie in to past and future activities at MPI-PKS.

15:00 - 16:00

Anushya Chandran
(Boston University)

Dissipative Cooling of Quantum Matter Using Light

I will review some aspects of dissipation engineering and describe our recent work demonstrating cavity-assisted cooling to target Floquet states.

Many-body Physics with Rydberg Atoms and Optical Dipoles

10:10 - 10:40

Philippe Suchsland
(MPIPKS)

Quantum Devices - From Qubits to Quantum Simulation

10:40 - 11:00

Coffee break

11:00 - 12:00

Roderich Moessner
(MPIPKS)

Fractionalisation and Fractals in a Topological Magnet

12:05 - 12:35

Felix Fritzsch
(MPIPKS)

Eigenstate Thermalization and Beyond

How do isolated quantum systems reach thermal equilibrium? Starting from an out-of-equilibrium pure state, unitary dynamics prevents the system to become a thermal mixed state and yet the physics at late times resemble thermal equilibrium. This apparent conundrum is resolved by the Eigenstate Thermalization Hypothesis (ETH), which conjectures eigenstates of an ergodic quantum Hamiltonian to be locally indistinguishable from thermal states. This is achieved by predicting the matrix elements of local observables to smoothly depend on the involved energies in a way that ensures thermalization. In this talk I will give a brief introduction to the ETH and its consequences, focusing in particular on the dynamics of correlation functions. In order to capture the latter in full generality, recently an extension, dubbed full ETH, has been proposed. After introducing full ETH I will sketch, how it allows for a systematic characterization of arbitrary correlation functions in terms of simple elementary building blocks by borrowing tools from the mathematical field of free probability.

12:35 - 13:30

Lunch at PKS

13:30 - 14:30

Julian Leonard
(TU Vienna)

Quantum Matter under the Microscope

14:40 - 15:40

Francesco Piazza
(University of Augsburg)

Introduction to Cavity-Quantum-Materials (and their collective behavior)

15:40 - 16:00

Coffee break

16:00 - 18:00

Markus Schmitt
(University of Regensburg)

Neural Quantum States to Simulate Non-equilibrium Matter

In 1929, the Swiss physicist Felix Bloch studied the Schrödinger equations with a periodic potential and discovered that the solution can be expressed as plane waves modulated by periodic functions. This result is known as “Bloch’s theorem” and constitutes a foundational building block of condensed matter physics. In this talk, I will introduce the Bloch states and their energy eigenvalues which give rise to the electronic band structure of crystalline solids. More recently, there is an increased interest in the properties of the Bloch states, such as the Berry curvature and the quantum metric. I conclude by showcasing where these properties play an important role in modern condensed matter physics, e.g., in topological insulators and superconductivity in non-dispersive bands.

09:40 - 10:10

Nan Tang
(University of Augsburg)

How to Probe Quantum Fluctuations by Experiments? Exploring the Magnetic Analogue of Ice: Quantum Spin Ice

10:10 - 10:40

Coffee break

10:40 - 11:40

Andy Mackenzie
(MPICPfS)

Designer Quantum Materials Experiments Enabled by Focused Ion Beam Sculpting

All magnetically ordered states of materials form by the collective ordering of spins, and spins are quantum mechanical objects, so one might think that quantum magnetism is really the only kind there can be. Strictly that's true; however, many magnets exhibit only weak entanglement between neighbouring spins, and thus can be thought of as approximately classical objects. In this lecture I will: (i) give an introduction to this distinction between classical and quantum magnetism; (ii) give rules of thumb for when quantum magnetism is likely to be energetically favourable; and (iii) give a couple of basic examples of the kind of states that result.

10:00 - 10:30

Coffee break

10:30 - 12:30

Discussion Panel: Ask the Experts

12:30 - 13:30

Lunch at PKS

13:30 - 15:30

Coding session with Alex Wietek / Lab Tour at MPICPfS

15:30 - 16:00

Coffee break

16:00 - 17:00

Linda Ye
(Caltech)

Lattice-driven Flat Bands in Quantum Materials

17:10 - 18:00

Suzy Zhang
(MPIPKS)

Aspects of Magnetic Transport: Frustration, Topology, and Dissipation

Magnetism in solids emerges from the interplay between quantum mechanics and many-body interactions. The study of transport properties of magnetic systems can provide significant insights into new phases of matter, exotic excitations, and their potential functionalities in technology innovation. This talk is a perspective based on my recent exploration of magnetic transport, from the aspects of geometric frustration, band topology, and dissipative dynamics, and connecting theoretical concepts to experimentally observable phenomena. I will focus on the first two aspects with the examples of the emergence of spin diffusion in the frustrated triangular-lattice magnet in the intermediate-temperature regime and the topological magnon polarons in van der Waals magnets and the resulted thermal Hall effect. Finally, I will briefly introduce the dissipative dynamics of a spin chain as an open quantum system and the non-Hermitian skin effect therein.

In this lecture I will show how to derive from phenomenological models the coupling between magnons and cavity photons in different frequency regimes, and discuss experimental signatures.

10:10 - 11:00

Reyhaneh Khasseh
(University of Augsburg)

Active Quantum Flocks

11:00 - 11:30

Coffee break

11:30 - 12:30

Hilary Noad
(MPICPfS)

Using Uniaxial Stress to Tune and Probe Quantum Materials