Publications by Fabian Essler

Shell-filling effect in the entanglement entropies of spinful fermions

Physical Review Letters 110 (2013)

FHL Essler, AM Läuchli, P Calabrese

We consider the von Neumann and Rényi entropies of the one-dimensional quarter-filled Hubbard model. We observe that for periodic boundary conditions the entropies exhibit an unexpected dependence on system size: for L=4 mod 8 the results are in agreement with expectations based on conformal field theory, while for L=0 mod 8 additional contributions arise. We explain this observation in terms of a shell-filling effect and develop a conformal field theory approach to calculate the extra term in the entropies. Similar shell-filling effects in entanglement entropies are expected to be present in higher dimensions and for other multicomponent systems. © 2013 American Physical Society.

Discrete symmetry breaking transitions between paired superfluids

PHYSICAL REVIEW A 85 (2012) ARTN 033636

MJ Bhaseen, S Ejima, FHL Essler, H Fehske, M Hohenadler, BD Simons

Dynamics in the Ising field theory after a quantum quench


D Schuricht, FHL Essler

Finite wave vector pairing in doped two-leg ladders

PHYSICAL REVIEW B 85 (2012) ARTN 195103

NJ Robinson, FHL Essler, E Jeckelmann, AM Tsvelik

Anomalous dynamical line shapes in a quantum magnet at finite temperature

PHYSICAL REVIEW B 85 (2012) ARTN 014402

DA Tennant, B Lake, AJA James, FHL Essler, S Notbohm, H-J Mikeska, J Fielden, P Koegerler, PC Canfield, MTF Telling

Observation of Complex Bound States in the Spin-1/2 Heisenberg XXZ Chain Using Local Quantum Quenches


M Ganahl, E Rabel, FHL Essler, HG Evertz

Quantum quench in the transverse-field Ising chain.

Phys Rev Lett 106 (2011) 227203-

P Calabrese, FHL Essler, M Fagotti

We consider the time evolution of observables in the transverse-field Ising chain after a sudden quench of the magnetic field. We provide exact analytical results for the asymptotic time and distance dependence of one- and two-point correlation functions of the order parameter. We employ two complementary approaches based on asymptotic evaluations of determinants and form-factor sums. We prove that the stationary value of the two-point correlation function is not thermal, but can be described by a generalized Gibbs ensemble (GGE). The approach to the stationary state can also be understood in terms of a GGE. We present a conjecture on how these results generalize to particular quenches in other integrable models.

Large deviation function for the current in the open asymmetric simple exclusion process.

Phys Rev Lett 107 (2011) 010602-

J de Gier, FHL Essler

We consider the one-dimensional asymmetric exclusion process with particle injection and extraction at two boundaries. The model is known to exhibit four distinct phases in its stationary state. We analyze the current statistics at the first site in the low and high density phases. In the limit of infinite system size, we conjecture an exact expression for the current large deviation function.

Ising deconfinement transition between Feshbach-resonant superfluids.

Phys Rev Lett 106 (2011) 015303-

S Ejima, MJ Bhaseen, M Hohenadler, FHL Essler, H Fehske, BD Simons

We investigate the phase diagram of bosons interacting via Feshbach-resonant pairing interactions in a one-dimensional lattice. Using large scale density matrix renormalization group and field theory techniques we explore the atomic and molecular correlations in this low-dimensional setting. We provide compelling evidence for an Ising deconfinement transition occurring between distinct superfluids and extract the Ising order parameter and correlation length of this unusual superfluid transition. This is supported by results for the entanglement entropy which reveal both the location of the transition and critical Ising degrees of freedom on the phase boundary.

Magnetic properties of the second Mott lobe in pairing Hamiltonians

PHYSICAL REVIEW A 84 (2011) ARTN 023635

MJ Bhaseen, S Ejima, M Hohenadler, AO Silver, FHL Essler, H Fehske, BD Simons

Phase diagram and continuous pair-unbinding transition of the bilinear-biquadratic S=1 Heisenberg chain in a magnetic field

PHYSICAL REVIEW B 83 (2011) ARTN 184433

SR Manmana, AM Laeuchli, FHL Essler, F Mila

Boundary effects on the local density of states of one-dimensional Mott insulators and charge density wave states

PHYSICAL REVIEW B 83 (2011) ARTN 035111

D Schuricht, FHL Essler, A Jaefari, E Fradkin

Effects of thermal phase fluctuations in a two-dimensional superconductor: an exact result for the spectral function.

Phys Rev Lett 105 (2010) 027002-

AM Tsvelik, FHL Essler

We consider the single particle spectral function for a two-dimensional clean superconductor in a regime of strong critical thermal phase fluctuations. In the limit where the maximum of the superconducting gap is much smaller than the Fermi energy we obtain an exact expression for the spectral function integrated over the momentum component perpendicular to the Fermi surface.

Low-temperature dynamical structure factor of the two-leg spin-1/2 Heisenberg ladder

PHYSICAL REVIEW B 82 (2010) ARTN 104417

WD Goetze, U Karahasanovic, FHL Essler

Universal corrections to scaling for block entanglement in spin-1/2 XX chains


P Calabrese, FHL Essler

Threshold singularities in the one-dimensional Hubbard model

PHYSICAL REVIEW B 81 (2010) ARTN 205120

FHL Essler

Parity Effects in the Scaling of Block Entanglement in Gapless Spin Chains


P Calabrese, M Campostrini, F Essler, B Nienhuis

Finite-temperature dynamical correlations in massive integrable quantum field theories


FHL Essler, RM Konik

Finite-temperature dynamical structure factor of the Heisenberg-Ising chain

PHYSICAL REVIEW B 79 (2009) ARTN 214408

AJA James, WD Goetze, FHL Essler

On the spin-liquid phase of one-dimensional spin-1 bosons


FHL Essler, GV Shlyapnikov, AM Tsvelik