Non-local order in Mott insulators, Duality and Wilson Loops

It is shown that the Mott insulating and superfluid phases of bosons in an optical lattice may be distinguished by a non-local 'parity order parameter' which is directly accessible via single site resolution imaging. In one dimension, the lattice Bose model is dual to a classical interface roughening problem. We use known exact results from the latter to prove that the parity order parameter exhibits long range order in the Mott insulating phase, consistent with recent experiments by Endres et al. [Science 334, 200 (2011)]. In two spatial dimensions, the parity order parameter can be expressed in terms of an equal time Wilson loop of a non-trivial U(1) gauge theory in 2+1 dimensions which exhibits a transition between a Coulomb and a confining phase. The negative logarithm of the parity order parameter obeys a perimeter law in the Mott insulator and is enhanced by a logarithmic factor in the superfluid.Comment: published versio

Lattice simulations with Nf=2+1N_f=2+1 improved Wilson fermions at a fixed strange quark mass

The explicit breaking of chiral symmetry of the Wilson fermion action results in additive quark mass renormalization. Moreover, flavour singlet and non-singlet scalar currents acquire different renormalization constants with respect to continuum regularization schemes. This complicates keeping the renormalized strange quark mass fixed when varying the light quark mass in simulations with $N_f=2+1$ sea quark flavours. Here we present and validate our strategy within the CLS (Coordinated Lattice Simulations) effort to achieve this in simulations with non-perturbatively order-$a$ improved Wilson fermions. We also determine various combinations of renormalization constants and improvement coefficients.Comment: 18 pages, 11 Figures, V2: References added/updated, all fits rerun with improved statistics for ensemble N204, also using the final values for the improvement coefficients A and b_P-b_A (very minor impact), The figures have been replotted accordingly. (The differences with respect to V1 are invisible to the human eye). Minor change

Light-cone distribution amplitudes of the baryon octet

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using $N_f=2+1$ flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.Comment: Update to the version published in JHE

Resonant elastic X-ray scattering of antiferromagnetic superstructures in EuPtSi3_{3}

We report resonant elastic X-ray scattering (REXS) of long-range magnetic order in EuPtSi$_{\text{3}}$, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi$_{\text{3}}$ stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fan-like superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized REXS, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky--Moriya spin--orbit coupling of similar strength

Scale setting and the light baryon spectrum in Nf=2+1N_f=2+1 QCD with Wilson fermions

We determine the light baryon spectrum on ensembles generated by the Coordinated Lattice Simulations (CLS) effort, employing $N_f=2+1$ flavours of non-perturbatively improved Wilson fermions. The hadron masses are interpolated and extrapolated within the quark mass plane, utilizing three distinct trajectories, two of which intersect close to the physical quark mass point and the third one approaching the SU(3) chiral limit. The results are extrapolated to the continuum limit, utilizing six different lattice spacings ranging from $a\approx 0.10\,$fm down to below $0.04\,$fm. The light pion mass varies from $M_{\pi}\approx 429\,$MeV down to $127\,$MeV. In general, the spatial extent is kept larger than four times the inverse pion mass and larger than $2.3\,$fm, with additional small and large volume ensembles to investigate finite size effects. We determine the Wilson flow scales $\sqrt{t_{0,{\rm ph}}}=0.1449^{(7)}_{(9)}\,$fm and $t_0^*\approx t_{0,{\rm ph}}$ from the octet cascade ($\Xi$ baryon). Determining the light baryon spectrum in the continuum limit, we find the nucleon mass $m_N=941.7^{(6.5)}_{(7.6)}\,$MeV and the other stable baryon masses to agree with their experimental values within sub-percent level uncertainties. Moreover, we determine SU(3) and SU(2) chiral perturbation theory low energy constants, including the octet and the $\Omega$ baryon sigma~terms $\sigma_{\pi N}=43.9(4.7)\,$MeV, $\sigma_{\pi\Lambda}=28.2^{(4.3)}_{(5.4)}\,$MeV, $\sigma_{\pi\Sigma}=25.9^{(3.8)}_{(6.1)}\,$MeV, $\sigma_{\pi\Xi}=11.2^{(4.5)}_{(6.4)}\,$MeV and $\sigma_{\pi\Omega}=6.9^{(5.3)}_{(4.3)}\,$MeV, as well as various parameters, renormalization factors and improvement coefficients that are relevant for simulations with our lattice action.Comment: 128 pages, many figure

Dataset package for the manuscript "Topological aspects of multi-k\bm{k} antiferromagnetism in cubic rare-earth compounds"

<p><strong>Dataset 1:</strong></p><p><strong>Title:</strong> Magnetic phase diagrams of HoCu, ErCu, and TmCu for magnetic field along the [111] axis.</p><p><strong>Description:</strong></p><p>Maxima and points of inflection observed in AC magnetic susceptibility data are stored in "HoCu111_1.dat", "HoCu111_2.dat", "HoCu111_3.dat", "HoCu111_4.dat", "ErCu111_FS.dat", "ErCu111_TS.dat", "TmCu111_FS.dat", and "TmCu111_TS.dat". The first and second columns correspond to temperature and field values of these points, respectively.</p><p> </p><p><strong>Dataset 2:</strong></p><p><strong>Title:</strong> Magnetization and electrical transport properties of bulk TmCu at <i>T </i>= 2K for magnetic field along [111].</p><p><strong>Description:</strong></p><p>The field dependence of the magnetization, longitudinal electrical resistivity, and transverse electrical resistivity are stored in the files "TmCuMagnetization.dat", "TmCuRhoxx.dat", and "TmCuRhoxy.dat", respectively. Contributions to the transverse resistivity that are associated with the normal Hall effect are stored in "TmCuRhoxynormalHall.dat". Anomalous Hall effect contributions that are linear in the magnetization are stored in "TmCuRhoxyAHE.dat".</p><p> </p><p><strong>Dataset 3:</strong></p><p><strong>Title: </strong> Magnetic neutron diffraction intensity as a function of temperature in HoCu at zero magnetic field.</p><p><strong>Description:</strong></p><p>Magnetic neutron diffraction intensity, as recorded by means of rocking-scans of the sample at the single-crystal diffractometer HEiDi (FRMII, Garching), centered around the reciprocal-space position <i><strong>Q</strong></i>0 = (1.5, 1.5, 1), are presented in "HoCuNeutronDiffraction_Int.dat" in terms of a 81 times 25 matrix. The presented intensity is normalized to the monitor. The first index enumerates the momentum transfer difference with respect to the reciprocal-space position <i><strong>Q</strong></i>0 and the second index the temperatures. The respective values are stored in "HoCuNeutronDiffraction_Q.dat" and "HoCuNeutronDiffraction_T.dat".</p&gt

Resonant Elastic X-Ray Scattering of Antiferromagnetic Superstructures in EuPtSi3_3

We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi$_3$, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi$_3$ stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized resonant elastic x-ray scattering, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength

Resonant Elastic X-Ray Scattering of Antiferromagnetic Superstructures in EuPtSi 3

We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi3, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi3 stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized resonant elastic x-ray scattering, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength