SEMINARS

Our group seminar features talks on current research topics from the field of Quantum Information and Quantum Many-Body Physics, and in particular Tensor Networks, given both by group members and by external guest speakers.

If you are interested in receiving seminar announcements, please send an informal e-mail to schuch-office.quantum[at]univie.ac.at to be added to our mailing list.

› For info on past seminars click here.

2025 Summer Semester

During the 2025 summer semester, the Quantum Information & Quantum Many-Body Physics seminar takes place on Thursdays at 11:30 in the Erwin Schrödinger lecture hall (Boltzmanngasse 5, 5th floor). Occasionally, there might be additional seminars out of schedule, or seminars given online, as announced here.

Ilya Kull (University of Vienna)

Density functional theory
Abstract: This will be an introduction to density functional theory. I will try to cover the basics of its theoretical foundation as well as how it is actually used in practice.

(date/time/location: 20.03.2025, 11:30, Boltzmanngasse 5/Strudlhofgasse 4, 5th floor, Erwin Schrödinger lecture hall)

Johannes Wladika (University of Vienna)

The Toric Code and XCube Model as stabilizer codes
Abstract: The XCube model can be used as a toy model for studying fracton models. Some characteristic common features of fracton models are well known, such as the existence of immobile excitations, topology dependent ground state degeneracy and the possibility to grow these systems by coupling lower dimensional models to them. The goal of my talk will be to work out those features in the XCube model using the toric code as a 2D model to ease the understanding of the 3D XCube.

(date/time/location: 27.03.2025, 11:30, Boltzmanngasse 5/Strudlhofgasse 4, 5th floor, Erwin Schrödinger lecture hall)

Bram Vanhecke (University of Vienna)

Fixed-point differentiation of Tensor Network methods
Abstract: We will discuss recent work being performed in collaboration with Anna Francuz, Paul Brehmer, and researchers from Ghent University where we aim to differentiate a number of widely used tensor network methods: VUMPS, CTM, and "pulling through".
A slow didactical approach will be taken to introduce the key ideas of fixed-point differentiation and in particular VUMPS will be studied in detail.

(date/time/location: 03.04.2025, 11:30, Boltzmanngasse 5/Strudlhofgasse 4, 5th floor, Erwin Schrödinger lecture hall)

András Molnár (University of Vienna)

On Infinite Tensor Networks
Abstract: In this talk, I will explore how to talk about infinite systems, especially ones described by tensor networks. The talk will follow mostly arXiv:2504.00096, trying to isolate the structure that is necessary for defining infinite systems: inductive limits of Banach spaces. I will illustrate the construction by MPS and discuss how to apply it to MERA.

(date/time/location: 10.04.2025, 11:30, Boltzmanngasse 5/Strudlhofgasse 4, 5th floor, Erwin Schrödinger lecture hall)

Felix Dusel (Julius-Maximilians-Universität Würzburg)

Hyperbolic Kitaev Spin Liquids
Abstract: We analyze the Kitaev model on the {9, 3} hyperbolic lattice. The {9, 3} is formed by a regular tricoordinated tiling of nonagons, where the three-color coding of bonds according to the inequivalent Kitaev Ising spin couplings yields the natural generalization of the original Kitaev model for Euclidean regular honeycomb tiling. Upon investigation of the bulk spectrum for large finite size droplets, we identify a gapless chiral Z_2 spin liquid state featuring spontaneous time-reversal symmetry breaking. Due to its non-commutative translation group structure, such type of hyperbolic spin liquid is conjectured to feature chiral quasiparticles with a potentially non-Abelian Bloch profile.

(date/time/location: 22.04.2025, 11:30, Boltzmanngasse 9, 2nd floor, conference room)