13 citations · 31 across the 10 of their papers we have counts for
11 papers
Exact strong zero modes are generic in integrable spin systems with large anisotropy
Sascha Gehrmann
Strong zero modes (SZMs) are edge-localized operators that commute with the Hamiltonian up to corrections exponentially small in system size, yielding anomalously long edge coheren…
Exact Quantum Many-Body Scars by a generalized Matrix-Product Ansatz
Sascha Gehrmann, Fabian H. L. Essler
We construct exact eigenstates of quantum many-body systems with Hamiltonians that are not frustration-free in matrix product form, based on a local error cancellation ansatz motiv…
XYZ integrability the easy way
Paul Fendley, Sascha Gehrmann, Eric Vernier +1
Sutherland showed that the XYZ quantum spin-chain Hamiltonian commutes with the eight-vertex model transfer matrix, so that Baxter's subsequent tour de force proves the integrabili…
Exact strong zero modes in quantum circuits and spin chains with non-diagonal boundary conditions
Sascha Gehrmann, Fabian H. L. Essler
We construct exact strong zero mode operators (ESZM) in integrable quantum circuits and the spin-1/2 XXZ chain for general open boundary conditions, which break the bulk U(1) symme…
Quantum-group-invariant models: Bethe ansatz and finite-size spectrum
Holger Frahm, Sascha Gehrmann, Rafael I. Nepomechie +1
We consider the quantum integrable spin chain models associated with the Jimbo R-matrix based on the quantum affine algebra , subject to quantum-group-invariant boun…
Scaling limit of the ground state Bethe roots for the inhomogeneous XXZ spin- chain
Sascha Gehrmann, Gleb A. Kotousov, Sergei L. Lukyanov
It is known that for the Heisenberg XXZ spin- chain in the critical regime, the scaling limit of the vacuum Bethe roots yields an infinite set of numbers that coincide…
Finite-size spectrum of the staggered six-vertex model with antidiagonal boundary conditions
Holger Frahm, Sascha Gehrmann
The finite-size spectrum of the critical staggered six-vertex model with antidiagonal boundary conditions is studied. Similar to the case of periodic boundary conditions, we identi…
Scaling limit of the staggered six-vertex model with invariant boundary conditions
Holger Frahm, Sascha Gehrmann, Gleb A. Kotousov
We study the scaling limit of a statistical system, which is a special case of the integrable inhomogeneous six-vertex model. It possesses invarianc…
The spin chain and its finite-size spectrum
Holger Frahm, Sascha Gehrmann, Rafael I. Nepomechie +1
Using the analytic Bethe ansatz, we initiate a study of the scaling limit of the quasi-periodic spin chain. Supported by a detailed symmetry analysis, we determine the…
Integrable boundary conditions for staggered vertex models
Holger Frahm, Sascha Gehrmann
Yang-Baxter integrable vertex models with a generic -staggering can be expressed in terms of composite -matrices given in terms of the elementary -matr…
Finite size spectrum of the staggered six-vertex model with -invariant boundary conditions
Holger Frahm, Sascha Gehrmann
The finite size spectrum of the critical -staggered spin- XXZ model with quantum group invariant boundary conditions is studied. For a particular (self-dual) cho…