Munich Center for Quantum Science and Technology

Magnetoelastic effects in the metallic frustrated antiferromagnet CrB $_{2}$

Tadataka Watanabe, Mai Watanabe, Sakurako Suganuma +2

Hexagonal chromium diboride CrB $_{2}$ is a metallic frustrated antiferromagnet with a Néel temperature $T_{N} \sim$ 88 K. In CrB $_{2}$ , Cr 3 $d$ electrons not only give rise to localized…

Thermal Hall conductivity from semiclassical spin dynamics simulations: implementation and applications to chiral ferromagnets and Kitaev magnets

Ignacio Salgado-Linares, Alexander Mook, Léo Mangeolle +1

We investigate thermal Hall transport in magnetic systems, using semiclassical spin dynamics simulations. Building on a linear response framework, we discuss the intricacies of com…

Dynamical magnetic breakdown and quantum oscillations from hot spot scattering

Léo Mangeolle, Johannes Knolle

Quantum oscillations (QO) are a well-established probe of Fermi-surface (FS) geometry and in the presence of long-range density wave order can display new QO frequencies from recon…

Non-reciprocal spin excitations across the skyrmion-paramagnetic phase transition in MnSi

Tobias Weber, Karin Schmalzl, Johannes Waizner +3

The magnetic excitations of the skyrmion lattice in MnSi comprise a multitude of individual modes, which are non-reciprocal and thereby propagate unidirectionally. We report inelas…

Electromagnetic Response of a Half-Filled Chern Band near Topological Criticality

Xinlei Yue, Fabian Pichler, Michael Knap +1

We evaluate electromagnetic-response observables in a half-filled Chern band, across a topological phase transition between a composite Fermi liquid (CFL) and a Fermi liquid (FL) p…

False Vacuum Decay in Flat-Band Ferromagnets: Role of Quantum Geometry and Chiral Edge States

Fabian Pichler, Clemens Kuhlenkamp, Michael Knap

Dynamical control of quantum matter is a challenging, yet promising direction for probing strongly correlated states. Motivated by recent experiments in twisted MoTe $_{2}$ that demon…

Non-Reciprocal Zone Boundary Magnon Propagation in Cu $_{2}$ OSeO $_{3}$

Tobias Weber, Niclas Heinsdorf, Michal Stekiel +3

Inelastic neutron scattering in the chiral magnet Cu $_{2}$ OSeO $_{3}$ reveals strong non-reciprocal effects on magnon propagation at the boundary of the nuclear Brillouin zone. The non-…

Excited states from local effective Hamiltonians of matrix product states and their entanglement spectrum transition

Denise Cocchiarella, Mingru Yang, Yueshui Zhang +3

Solving excited states is a challenging task for interacting systems. For one-dimensional critical systems, however, excited states can be directly accessed from the eigenvectors o…

Additional quantum many-body scars of the spin- $1$ $X Y$ model with Fock-space cages and commutant algebras

Sashikanta Mohapatra, Sanjay Moudgalya, Ajit C. Balram

Quantum many-body scars (QMBS) represent a mechanism for weak ergodicity breaking, characterized by the coexistence of atypical non-thermal eigenstates within an otherwise thermali…

Simulating Topological Order on Quantum Processors

Adam Gammon-Smith, Michael Knap, Frank Pollmann

It is an ongoing quest to realize topologically ordered quantum states on different platforms including condensed matter systems, quantum simulators and digital quantum processors.…

Fate of Topological Dirac Magnons in van der Waals Ferromagnets at Finite Temperature

Rintaro Eto, Ignacio Salgado-Linares, Masahito Mochizuki +2

Dirac magnons, the bosonic counterparts of Dirac fermions in graphene, provide a unique platform to explore symmetry-protected band crossings and quantum geometry in magnetic insul…

cond-mat.str-el2025★ 3 cited

Spontaneously Broken Non-Invertible Symmetries in Transverse-Field Ising Qudit Chains

Kristian Tyn Kai Chung, Umberto Borla, Andriy H. Nevidomskyy +1

Recent developments have revealed that symmetries need not form a group, but instead can be non-invertible. Here we use analytical arguments and numerical evidence to illuminate ho…

Continuous topological phase transition between $Z_{2}$ topologically ordered phases

Qi Zhang, Wen-Tao Xu

Topological phase transitions beyond anyon condensation remain poorly understood. A notable example is the transition between the toric code (TC) and double semion (DS) phases, whi…

Phases of Interacting Fibonacci Anyons on a Ladder at Half-Filling

Nico Kirchner, Roderich Moessner, Frank Pollmann +1

Two-dimensional many-body quantum systems can exhibit topological order and support collective excitations with anyonic statistics different from the usual fermionic or bosonic one…

Diagonal Isometric Form for Tensor Network States in Two Dimensions

Benjamin Sappler, Masataka Kawano, Michael P Zaletel +1

Isometric tensor network states (isoTNS) generalize the isometric form of the one-dimensional matrix product states (MPS) to tensor networks in two and higher dimensions. Here, we…

cond-mat.str-el2025★ 16 cited

Order-by-disorder in magnets with frustrated spin interactions -- classical and large- $S$ limits via the spin functional integral

Peng Rao, Johannes Knolle

We investigate spin systems with extensive degeneracies in the classical ground states due to anisotropic frustrated spin interactions, where the degeneracy is not protected by sym…

Microscopic Mechanism of Anyon Superconductivity Emerging from Fractional Chern Insulators

Fabian Pichler, Clemens Kuhlenkamp, Michael Knap +1

Fractional quantum Hall (FQH) states and superconductors typically require contrasting conditions, yet recent experiments have observed them in the same device. A natural explanati…

Theory of Angle Resolved Photoemission Spectroscopy of Altermagnetic Mott Insulators

Lorenzo Lanzini, Purnendu Das, Michael Knap

Altermagnetism has emerged as an unconventional form of collinear magnetism with spatial rotational symmetries, that give rise to strongly spin-split bands despite of an underlying…

Topology meets symmetry breaking: Hidden order, intrinsically gapless topological states and finite-temperature topological transitions

Reja H. Wilke, Henning Schlömer, Simon M. Linsel +2

Since the discovery of phase transitions driven by topological defects, the classification of phases of matter has been significantly extended beyond Ginzburg and Landau's paradigm…

High-temperature series expansion of the dynamic Matsubara spin correlator

Ruben Burkard, Benedikt Schneider, Björn Sbierski

The high-temperature series expansion for quantum spin models is a well-established tool to compute thermodynamic quantities and equal-time spin correlations, in particular for fru…

Coupling quantum spin ice to matter on the centered pyrochlore lattice

Rajah P. Nutakki, Sylvain Capponi, Ludovic D. C. Jaubert +1

The low-energy physics of quantum spin ice is known to support an emergent form of quantum electrodynamics (QED), where magnetic monopoles exist and the fine structure constant is…

Dynamic correlations of frustrated quantum spins from high-temperature expansion

Ruben Burkard, Benedikt Schneider, Björn Sbierski

For quantum spin systems in equilibrium, the dynamic structure factor (DSF) is among the most feature-packed experimental observables. However, from a theory perspective it is ofte…

Extrinsic contribution to bosonic thermal Hall transport

Léo Mangeolle, Johannes Knolle

Bosonic excitations like phonons and magnons dominate the low-temperature transport of magnetic insulators. Similar to electronic Hall responses, the thermal Hall effect (THE) of c…