Absence of barren plateaus in finite local-depth circuits with long-range entanglement

HK Zhang, S Liu, SX Zhang - Physical Review Letters, 2024 - APS
Ground state preparation is classically intractable for general Hamiltonians. On quantum
devices, shallow parametrized circuits can be effectively trained to obtain short-range …

Entanglement properties of gauge theories from higher-form symmetries

WT Xu, T Rakovszky, M Knap, F Pollmann - Physical Review X, 2025 - APS
We explore the relationship between higher-form symmetries and entanglement properties
in lattice gauge theories with discrete gauge groups, which can exhibit both topologically …

Topological quantum phase transitions in 2D isometric tensor networks

YJ Liu, K Shtengel, F Pollmann - arxiv preprint arxiv:2312.05079, 2023 - arxiv.org
Isometric tensor networks (isoTNS) form a subclass of tensor network states that have an
additional isometric condition, which implies that they can be efficiently prepared with a …

Critical behavior of the Fredenhagen-Marcu order parameter at topological phase transitions

WT Xu, F Pollmann, M Knap - arxiv preprint arxiv:2402.00127, 2024 - arxiv.org
A nonlocal string order parameter detecting topological phase transitions has been
proposed by Fredenhagen and Marcu (FM). In this work, we find that the FM string order …

Simulating two-dimensional topological quantum phase transitions on a digital quantum computer

YJ Liu, K Shtengel, F Pollmann - Physical Review Research, 2024 - APS
Efficient preparation of many-body ground states is key to harnessing the power of quantum
computers in studying quantum many-body systems. In this work, we propose a simple …

Solvable models for 2+ 1D quantum critical points: Loop soups of 1+ 1D conformal field theories

A Moharramipour, D Sehayek, T Scaffidi - SciPost Physics, 2024 - scipost.org
We construct a class of solvable models for 2+ 1D quantum critical points by attaching 1+ 1D
conformal field theories (CFTs) to fluctuating domain walls forming a" loop soup" …

Bridging Rokhsar-Kivelson type and generic quantum phase transitions via thermofield double states

WT Xu, RZ Huang, GM Zhang - Physical Review B, 2024 - APS
The formalism of the Rokhsar-Kivelson (RK) model has been frequently used to study
topological phase transitions in 2D in terms of the deformed wave functions, which are RK …

Quantum Phase Transitions between Symmetry-Enriched Fracton Phases

J Boesl, YJ Liu, WT Xu, F Pollmann, M Knap - arxiv preprint arxiv …, 2025 - arxiv.org
Phases with topological order exhibit further complexity in the presence of global
symmetries: States with the same topological order are distinguished by how their anyonic …

Boundary anomaly detection in two-dimensional subsystem symmetry-protected topological phases

K Ding, HR Zhang, BT Liu, S Yang - arxiv preprint arxiv:2412.07563, 2024 - arxiv.org
We develop a method to detect quantum anomalies in systems with subsystem symmetry,
building on the concept of anomaly indicators. This approach allows us to distinguish …

Finite Entanglement Scaling of Disorder Parameter at Quantum Criticality

WT Xu, RZ Huang - arxiv preprint arxiv:2411.01009, 2024 - arxiv.org
The disorder parameter, which is the expectation value of the symmetry transformation
acting on a subsystem, can be used to characterize symmetric phases as an analogy to …