Publications de Andreas Martin Läuchli Herzig

Self-congruent point in critical matrix product states: An effective field theory for finite-entanglement scaling

We set up an effective field theory formulation for the renormalization flow of matrix product states (MPS) with finite bond dimension, focusing on systems exhibiting finite-entanglement scaling close to a conformally invariant critical fixed point. We sho ...

2025

Thermalization and criticality on an analogue-digital quantum simulator

Andreas Martin Läuchli Herzig

Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators(1,2). Unlocking the full potential of such systems towards this goal requires flexible initial state preparation, precise time evolution and ext ...

NATURE PORTFOLIO2025

Microscopic Origin of Reduced Magnetic Order in a Frustrated Metal

Andreas Martin Läuchli Herzig

Although magnetic frustration in metals provides a promising avenue for novel quantum phenomena, their microscopic interpretation is often challenging. Here, we use the face-centered cubic intermetallic HoInCu_{4} as model material to show that Hamiltonian ...

2025

Fingerprints of supersymmetric spin and charge dynamics observed by inelastic neutron scattering

Andreas Martin Läuchli Herzig, Bruce Normand

Supersymmetry is an algebraic property of a quantum Hamiltonian that, by giving every boson a fermionic superpartner and vice versa, may underpin physics beyond the Standard Model. Fractional bosonic and fermionic quasiparticles are familiar in condensed m ...

NATURE PORTFOLIO2025

Variational benchmarks for quantum many-body problems

Andreas Martin Läuchli Herzig, Giuseppe Carleo, Dian Wu, Filippo Vicentini, Riccardo Rossi, Jannes Willy E. Nys

The continued development of computational approaches to many-body ground-state problems in physics and chemistry calls for a consistent way to assess its overall progress. In this work, we introduce a metric of variational accuracy, the V-score, obtained ...

American Association for the Advancement of Science2024

Benchmarking quantum computer simulation software packages: State vector simulators

Andreas Martin Läuchli Herzig

Rapid advances in quantum computing technology lead to an increasing need for software simulators that enable both algorithm design and the validation of results obtained from quantum hardware. This includes calculations that aim at probing regimes of quan ...

SCIPOST FOUNDATION2024

Quantum Spin Dynamics Due to Strong Kitaev Interactions in the Triangular-Lattice Antiferromagnet CsCeSe2

Andreas Martin Läuchli Herzig

The extraordinary properties of the Kitaev model have motivated an intense search for new physics in materials that combine geometrical and bond frustration. In this Letter, we employ inelastic neutron scattering, spin wave theory, and exact diagonalizatio ...

AMER PHYSICAL SOC2024

Quantum Electrodynamics in 2+1 Dimensions as the Organizing Principle of a Triangular Lattice Antiferromagnet

Andreas Martin Läuchli Herzig

Quantum electrodynamics in 2 thorn 1 dimensions (QED(3)) has been proposed as a critical field theory describing the low-energy effective theory of a putative algebraic Dirac spin liquid or of quantum phase transitions in two-dimensional frustrated magnets ...

American Physical Society2024

Stripe magnetic order and field-induced quantum criticality in the perfect triangular-lattice antiferromagnet CsCeSe2

Andreas Martin Läuchli Herzig

The two-dimensional triangular-lattice antiferromagnet (TLAF) is a textbook example of frustrated magnetic systems. Despite its simplicity, the TLAF model exhibits a highly rich and complex magnetic phase diagram, featuring numerous distinct ground states ...

AMER PHYSICAL SOC2024

Emergent Conformal Boundaries from Finite-Entanglement Scaling in Matrix Product States

Andreas Martin Läuchli Herzig

The use of finite entanglement scaling with matrix product states (MPS) has become a crucial tool for studying one-dimensional critical lattice theories, especially those with emergent conformal symmetry. We argue that finite entanglement introduces a rele ...

Amer Physical Soc2024

Ideal Chern bands with strong short-range repulsion: Applications to correlated metals, superconductivity, and topological order

Andreas Martin Läuchli Herzig

Motivated by recent experiments on correlated van der Waals materials, including twisted and rhombohedral graphene and twisted WSe2, we perform an analytical and numerical study of the effects of strong on-site and short-range interactions in fractionally ...

AMER PHYSICAL SOC2024

Supersymmetry on the honeycomb lattice: Resonating charge stripes, superfrustration, and domain walls

Andreas Martin Läuchli Herzig

We study a model of spinless fermions on the honeycomb lattice with nearest-neighbor exclusion and extended repulsive interactions that exhibits "lattice supersymmetry" [P. Fendley et al., , Phys. Rev. Lett. 90 , 120402 (2003)]. Using a combination of exac ...

AMER PHYSICAL SOC2024

Continuous symmetry breaking in a two-dimensional Rydberg array

Andreas Martin Läuchli Herzig

Spontaneous symmetry breaking underlies much of our classification of phases of matter and their associated transitions(1-3). The nature of the underlying symmetry being broken determines many of the qualitative properties of the phase; this is illustrated ...

2023

Complete field-induced spectral response of the spin-1/2 triangular-lattice antiferromagnet CsYbSe2

Andreas Martin Läuchli Herzig, Bruce Normand

Fifty years after Anderson's resonating valence-bond proposal, the spin-1/2 triangular-lattice Heisenberg antiferromagnet (TLHAF) remains the ultimate platform to explore highly entangled quantum spin states in proximity to magnetic order. Yb-based delafos ...

Nature Portfolio2023

Emergent XY* transition driven by symmetry fractionalization and anyon condensation

Andreas Martin Läuchli Herzig

Anyons in a topologically ordered phase can carry fractional quantum numbers with re-spect to the symmetry group of the considered system, one example being the fractional charge of the quasiparticles and quasiholes in the fractional quantum Hall effect. W ...

2023

Extracting the Speed of Light from Matrix Product States

Andreas Martin Läuchli Herzig

We provide evidence that the spectrum of the local effective Hamiltonian and the transfer operator in infinite-system matrix product state simulations are identical up to a global rescaling factor, i.e., the speed of light of the system, when the underlyin ...

2023

Diabatic quantum and classical annealing of the Sherrington-Kirkpatrick model

Andreas Martin Läuchli Herzig

Quantum annealing is a contender to solve combinatorial optimization problems based on quantum dynamics. While significant efforts have been undertaken to investigate the quality of the solutions and the required run times, much less attention has been pai ...

AMER PHYSICAL SOC2023

Symmetric projected entangled-pair states analysis of a phase transition in coupled spin- 1/2 ladders

Andreas Martin Läuchli Herzig

Infinite projected entangled-pair states (iPEPS) have been introduced to accurately describe many-body wave functions on two-dimensional lattices. In this context, two aspects are crucial: the systematic improvement of the Ansatz by the optimization of its ...

2022

Dynamics of a pair of magnetic dipoles with nonreciprocal interactions due to a moving conductor

Andreas Martin Läuchli Herzig

Recently it was demonstrated theoretically and experimentally that the presence of a moving conductor can break the reciprocity in the interactions between magnetic dipoles. In this article we investigate the influence of nonreciprocity on the dynamics of ...

2022

Thermal Evolution of Dirac Magnons in the Honeycomb Ferromagnet CrBr3

Andreas Martin Läuchli Herzig, Bruce Normand, Christian Rüegg

CrBr3 is an excellent realization of the two-dimensional honeycomb ferromagnet, which offers a bosonic equivalent of graphene with Dirac magnons and topological character. We perform inelastic neutron scattering measurements using state-of-the-art instrume ...

2022