arXiv subjects

Heloise Nonne

Publications and source records attributed to Heloise Nonne.

3 recordsLinked to original sources

arXiv2015

Collective modes in a quantum solid

We provide a theoretical explanation for the optical modes observed in inelastic neutron scattering (INS) on the bcc solid phase of helium 4 [T. Markovich, E. Polturak, J. Bossy, and E. Farhi, Phys. Rev. Lett. 88, 195301 (2002)]. We argue that these excitations are amplitude (Higgs) modes associated with fluctuations of the crystal order parameter within the unit cell. We present an analysis of the modes based on an effective Ginzburg-Landau model, classify them according to their symmetry properties, and compute their signature in INS experiments. In addition, we calculate the dynamical structure factor by means of an ab intio quantum Monte Carlo simulation and find a finite frequency excitation at zero relative momentum.

cond-mat.str-el↗

arXiv2014

Competing Valence Bond States of Spin-3/2 Fermions on a Strongly Coupled Ladder

We study the possible ground state configurations of two strongly coupled chains of charge neutral spin-3/2 fermionic atoms interacting via short range van der Waals interaction. The coupling between the two chains is realized by relatively large hopping amplitude. Exploiting that such a ladder configuration can be mapped to an effective one-band model we analyze the emerging ground states of the system. We show that various spatially inhomogeneous states, valence bond states, plaquette states compete depending on the filling and the ratio of the interaction strengths in the singlet and quintet scattering channel. We find that a Luttinger liquid state is the ground state of the strongly coupled ladder in an extended region of the parameter space, and we also show that a topologically nontrivial charge Haldane state can emerge in the strongly coupled ladder at quarter and three-quarter fillings.

cond-mat.str-el↗

arXiv2010

Phase diagram of one-dimensional earth-alkaline cold fermionic atoms

The phase diagram of one-dimensional earth-alkaline fermionic atoms and ytterbium 171 atoms is investigated by means of a low-energy approach and density-matrix renormalization group calculations. For incommensurate filling, four gapless phases with a spin gap are found and consist of two superconducting instabilities and two coexisting bond and charge density-waves instabilities. In the half-filled case, seven Mott-insulating phases arise with the emergence of four non-degenerate phases with exotic hidden orderings.

cond-mat.quant-gas↗