arXiv subjects

Leslie O. Baksmaty

Publications and source records attributed to Leslie O. Baksmaty.

4 recordsLinked to original sources

arXiv2011

Single Impurity In Ultracold Fermi Superfluids

The role of impurities as experimental probes in the detection of quantum material properties is well appreciated. Here we study the effect of a single classical magnetic impurity in trapped ultracold Fermi superfluids. Depending on its shape and strength, a magnetic impurity can induce single or multiple mid-gap bound states in a superfluid Fermi gas. The multiple mid-gap states could coincide with the development of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase within the superfluid. As an analog of the Scanning Tunneling Microscope, we propose a modified RF spectroscopic method to measure the local density of states which can be employed to detect these states and other quantum phases of cold atoms. A key result of our self consistent Bogoliubov-de Gennes calculations is that a magnetic impurity can controllably induce an FFLO state at currently accessible experimental parameters.

cond-mat.quant-gas↗

arXiv2008

Nonuniversal transmission phase lapses through a quantum dot: An exact-diagonalization of the many-body transport problem

Systematic trends of nonuniversal behavior of electron transmission phases through a quantum dot, with no phase lapse for the transition N=1 -> N=2 and a lapse of pi for the N=2 -> N=3 transition, are predicted, in agreement with experiments, from many-body transport calculations involving exact diagonalization of the dot Hamiltonian. The results favor shape anisotropy of the dot and strong e-e repulsion with consequent electron localization, showing dependence on spin configurations and the participation of excited doorway transmission channels.

cond-mat.mes-hall↗

arXiv2007

Rapidly rotating boson molecules with long or short range repulsion: an exact diagonalization study

The Hamiltonian for a small number, N <= 11, of bosons in a rapidly rotating harmonic trap, interacting via a short range (contact potential) or a long range (Coulomb) interaction, is studied via an exact diagonalization in the lowest Landau level. Our analysis shows that, for both low and high fractional fillings, the bosons localize and form rotating boson molecules (RBMs) consisting of concentric polygonal rings. Focusing on systems with the number of trapped atoms sufficiently large to form multi-ring bosonic molecules, we find that, as a function of the rotational frequency and regardless of the type of repulsive interaction, the ground-state angular momenta grow in specific steps that coincide with the number of localized bosons on each concentric ring. Comparison of the conditional probability distributions (CPDs) for both interactions suggests that the degree of crystalline correlations appears to depend more on the fractional filling nu than on the range of the interaction. The RBMs behave as nonrigid rotors, i.e., the concentric rings rotate independently of each other. At filling fractions nu < 1/2, we observe well developed crystallinity in the CPDs (two-point correlation functions). For larger filling fractions nu > 1/2, observation of similar molecular patterns requires consideration of even higher-order correlation functions.

cond-mat.mes-hall↗

arXiv2006

Bosonic molecules in rotating traps

We present a variational many-body wave function for repelling bosons in rotating traps, focusing on rotational frequencies that do not lead to restriction to the lowest Landau level. This wave function incorporates correlations beyond the Gross-Pitaevskii (GP) mean field approximation, and it describes rotating boson molecules (RBMs) made of localized bosons that form polygonal-ring-like crystalline patterns in their intrinsic frame of reference. The RBMs exhibit characteristic periodic dependencies of the ground-state angular momenta on the number of bosons in the polygonal rings. For small numbers of neutral bosons, the RBM ground-state energies are found to be always lower than those of the corresponding GP solutions, in particular in the regime of GP vortex formation.

cond-mat.soft↗