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Frédéric Mila

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Publications associées (204)

Phase separation versus supersolid behavior in frustrated antiferromagnets

Jean-David Picon, Frédéric Mila, Nicolas Laflorencie

We investigate the competition between spin supersolidity and phase separation in a frustrated spin-half model of weakly coupled dimers. We start by considering systems of hard-core bosons on the square lattice, onto which the low-energy physics of the her ...

2011

Simultaneous Dimerization and SU(4) Symmetry Breaking of 4-Color Fermions on the Square Lattice

Frédéric Mila, Karlo Penc

Using infinite projected entangled-pair states, exact diagonalization, and flavor-wave theory, we show that the SU(4) Heisenberg model undergoes a spontaneous dimerization on the square lattice, in contrast with its SU(2) and SU(3) counterparts, which deve ...

2011

Condensate-Free Superfluid Induced by the Frustrated Proximity Effect

Frédéric Mila, Nicolas Laflorencie

Since the discovery of superfluidity in He-4 and Landau's phenomenological theory, the relationship between Bose condensation and superfluidity has been intensely debated. He-4 is known by now to be both superfluid and condensed at low temperature, and mor ...

2011

Ferrimagnetism of the magnetoelectric compound Cu2OSeO3 probed by Se-77 NMR

Jean-Philippe Ansermet, Helmuth Berger, Frédéric Mila

We present a thorough Se-77 nuclear-magnetic-resonance (NMR) study of a single crystal of the magnetoelectric compound Cu2OSeO3. The temperature dependence of the local electronic moments extracted from the NMR data is fully consistent with a magnetic phas ...

2010

Three-Sublattice Ordering of the SU(3) Heisenberg Model of Three-Flavor Fermions on the Square and Cubic Lattices

Frédéric Mila, Karlo Penc, Tamás András Tóth

Combining a semiclassical analysis with exact diagonalizations, we show that the ground state of the SU(3) Heisenberg model on the square lattice develops three-sublattice long-range order. This surprising pattern for a bipartite lattice with only nearest- ...

2010

Chirality of Triangular Antiferromagnetic Clusters as a Qubit

Frédéric Mila

We show that the chirality of triangular antiferromagnetic clusters can be used as a qubit even if it is entirely decoupled from the total spin of the cluster. In particular, we estimate the orbital moment associated with the chirality, and we show that it ...

2010

Effective Spin Model for the Spin-Liquid Phase of the Hubbard Model on the Triangular Lattice

Frédéric Mila, Hongyu Yang

We show that the spin-liquid phase of the half-filled Hubbard model on the triangular lattice can be described by a pure spin model. This is based on a high-order strong coupling expansion ( up to order 12) using perturbative continuous unitary transformat ...

2010

Frustration- induced plateaus in S >= 1/2 Heisenberg spin ladders

Jean-David Picon, Frédéric Mila, Tommaso Coletta, Frédéric Alexis Michaud, Salvatore Manmana

We study the T=0 magnetization of frustrated two-leg spin ladders with arbitrary value of the spin S. In the strong-rung limit, we use degenerate perturbation theory to prove that frustration leads to magnetization plateaus at fractional values of the magn ...

2010

Orbital Currents in Extended Hubbard Models of High-T-c Cuprate Superconductors

Cédric Weber, Frédéric Mila, Thierry Giamarchi

Motivated by the recent report of broken time-reversal symmetry and zero momentum magnetic scattering in underdoped cuprates, we investigate under which circumstances orbital currents circulating inside a unit cell might be stabilized in extended Hubbard m ...

2009

Theory of the Field-Induced BEC in the Frustrated Spin-1/2 Dimer Compound BaCuSi2O6

Frédéric Mila, Nicolas Laflorencie

Building on recent neutron and NMR experiments, we investigate the field-induced exotic criticality observed in the frustrated compound BaCuSi2O6 using a frustrated model with two types of bilayers. A semiclassical treatment of the effective hard-core boso ...

2009

Spin-Peierls instabilities of antiferromagnetic rings in a magnetic field

Frédéric Mila, Karlo Penc, Ioannis Rousochatzakis

Motivated by the intriguing properties of magnetic molecular wheels at field-induced level crossings, we investigate the spin-Peierls instability of antiferromagnetic rings in a field by exact diagonalizations of a microscopic spin model coupled to the lat ...

2009

Dzyaloshinskii-Moriya anisotropy and nonmagnetic impurities in the s=1/2 kagome system ZnCu3(OH)(6)Cl-2

Frédéric Mila, Ioannis Rousochatzakis, Bruce Normand, Salvatore Manmana

Motivated by recent nuclear magnetic resonance experiments on ZnCu3(OH)(6)Cl-2, we present an exact-diagonalization study of the combined effects of nonmagnetic impurities and Dzyaloshinskii-Moriya (DM) interactions in the s = 1/2 kagome antiferromagnet. T ...

2009

Torque anomalies at magnetization plateaux in quantum magnets with Dzyaloshinskii-Moriya interactions

Frédéric Mila, Salvatore Manmana

We investigate the effect of Dzyaloshinskii-Moriya (DM) interactions on torque measurements of quantum magnets with magnetization plateaux in the context of a frustrated spin-1/2 ladder. Using extensive DMRG simulations, we show that the DM contribution to ...

2009

Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu2(BO3)(2) doped with nonmagnetic impurities

Frédéric Mila

Controlled doping of SrCu2(BO3)(2), a faithful realization of the Heisenberg spin-1/2 antiferromagnet on the Shastry-Sutherland lattice, with nonmagnetic impurities generates bound states below the spin gap. These bound states and their symmetry properties ...

2009

Magnetization plateaux in an extended Shastry-Sutherland model

Frédéric Mila, Julien Dorier

We study an extended two-dimensional Shastry-Sutherland model in a magnetic field where besides the usual Heisenberg exchanges of the Shastry-Sutherland model two additional SU(2) invariant couplings are included. Perturbative continous unitary transformat ...

2009

Highly frustrated magnetic clusters: The kagome on a sphere

Frédéric Mila, Ioannis Rousochatzakis

We present a detailed study of the low-energy excitations of two existing finite-size realizations of the planar kagome Heisenberg antiferromagnet on the sphere: the cuboctahedron and the icosidodecahedron. After highlighting a number of special spectral f ...

2008

Two-dimensional quantum antiferromagnet with a fourfold degenerate dimer ground state

Frédéric Mila

We study the competition between antiferromagnetic order and valence-bond-crystal formation in a two-dimensional frustrated spin-1/2 model. The J(1)-J(2) model on the square lattice is further frustrated by introducing products of three-spin projectors whi ...

2008

Quantum dimer model on the triangular lattice: Semiclassical and variational approaches to vison dispersion and condensation

Frédéric Mila

After reviewing the concept of vison excitations in Z(2) dimer liquids, we study the liquid-crystal transition of the quantum dimer model on the triangular lattice by means of a semiclassical spin-wave approximation to the dispersion of visons in the conte ...

2008

Supersolid Phases of Hardcore Bosons on the Square Lattice: Correlated Hopping, Next-Nearest Neighbor Hopping and Frustration

Frédéric Mila, Julien Dorier

We discuss the appearance of supersolid phases for interacting hardcore bosons on the square lattice when, in addition to the standard nearest neighbor hopping and repulsion, correlated or next-nearest neighbor hopping is present. Having in mind dimer-base ...

2008

Theory of Magnetization Plateaux in the Shastry-Sutherland Model

Frédéric Mila, Julien Dorier

Motivated by the remarkable properties of SrCu2(BO3)(2) in a magnetic field, we use perturbative continuous unitary transformations to determine the magnetization plateaux of the Shastry-Sutherland model, unveiling an unexpected sequence of plateaux progre ...

2008

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