Cooling Quantum Gases with Entropy Localization

We study the dynamics of entropy in a time dependent potential and explore how disorder influences this entropy flow. We show that disorder can trap entropy at the edge of the atomic cloud enabling a novel cooling method. We demonstrate the feasibility of our cooling technique by analyzing the evolution of entropy in a one-dimensional Fermi lattice gas with a time dependent superlattice potential.Comment: 6 pages, 4 figure

Floquet engineering of optical solenoids and quantized charge pumping along tailored paths in two-dimensional Chern insulators

The insertion of a local magnetic flux, as the one created by a thin solenoid, plays an important role in gedanken experiments of quantum Hall physics. By combining Floquet engineering of artificial magnetic fields with the ability of single-site addressing in quantum-gas microscopes, we propose a scheme for the realization of such local solenoid-type magnetic fields in optical lattices. We show that it can be employed to manipulate and probe elementary excitations of a topological Chern insulator. This includes quantized adiabatic charge pumping along tailored paths inside the bulk, as well as the controlled population of edge modes.Comment: 6 pages, 4 figures. Discussions and references are update

Wave packet dynamics and edge transport in anomalous Floquet topological phases

The possibility of attaining chiral edge modes under periodic driving has spurred tremendous attention, both theoretically and experimentally, especially in light of anomalous Floquet topological phases that feature vanishing Chern numbers unlike any static counterpart. We here consider a periodically modulated honeycomb lattice and experimentally relevant driving protocols, which allows us to obtain edge modes of various character in a simple model. We calculate the phase diagram over a wide range of parameters and recover an anomalous topological phase with quasienergy gaps harbouring edge states with opposite chirality. Motivated by the advances in single-site control in optical lattices, we investigate wave packet dynamics localized at the edges in distinct Floquet topological regimes that cannot be achieved in equilibrium. We analyse transport properties in edge modes originating from the same bands, but with support at different quasienergies and sublattices as well as possessing different chiralities. We find that an anomalous Floquet topological phase can in general generate more robust chiral edge motion than a Haldane phase. Our results demonstrate that the rich interplay of wave packet dynamics and topological edge states can serve as a versatile tool in ultracold quantum gases in optical lattices.Comment: 9+2 pages, 7+3 figure

Speaking and gesturing guide event perception during message conceptualization: Evidence from eye movements

Speakers’ visual attention to events is guided by linguistic conceptualization of information in spoken language production and in language-specific ways. Does production of language-specific co-speech gestures further guide speakers’ visual attention during message preparation? Here, we examine the link between visual attention and multimodal event descriptions in Turkish. Turkish is a verb-framed language where speakers’ speech and gesture show language specificity with path of motion mostly expressed within the main verb accompanied by path gestures. Turkish-speaking adults viewed motion events while their eye movements were recorded during non- linguistic (viewing-only) and linguistic (viewing-before-describing) tasks. The relative attention allocated to path over manner was higher in the linguistic task compared to the non-linguistic task. Furthermore, the relative attention allocated to path over manner within the linguistic task was higher when speakers (a) encoded path in the main verb versus outside the verb and (b) used additional path gestures accompanying speech versus not. Results strongly suggest that speakers’ visual attention is guided by language-specific event encoding not only in speech but also in gesture. This provides evidence consistent with models that propose integration of speech and gesture at the conceptualization level of language production and suggests that the links between the eye and the mouth may be extended to the eye and the hand

How to Directly Measure Floquet Topological Invariants in Optical Lattices

The classification of topological Floquet systems with time-periodic Hamiltonians transcends that of static systems. For example, spinless fermions in periodically driven two-dimensional lattices are not completely characterized by the Chern numbers of the quasienergy bands, but rather by a set of winding numbers associated with the quasienergy gaps. We propose a scheme for measuring these winding numbers in a system of fermionic cold atoms in a periodically driven optical lattice efficiently and directly. It is based on the construction of a one-parameter family of experimentally feasible drives, continuously connecting the Floquet system of interest to a trivial reference system. The winding numbers are then determined by the identification and the tomography of the band-touching singularities occurring on the way. As a byproduct, we also propose a method for probing spectral properties of time evolution operators via a time analog of crystallography.Comment: 6 pages, 5 figure

Serum lipids in Turkish patients with β-thalassemia major and β-thalassemia minor

It is well-known that β-thalassemia is associated with changes in plasma lipids and lipoproteins [1,2,3]. To our knowledge, no data are available on lipid profiles in Turkish β-thalassemia major (TM) and β-thalassemia trait (TT) patients together. The aim of this study was to evaluate lipid profiles in two groups of patients with β-TM and β-TT and to compare them with healthy controls. The study included a total of 311 subjects. Group 1 included 131 β-TM patients (mean age: 16.3±7.58 years). Group 2 included 68 β-TT patients (mean age: 7.25±4.43 years). Group 3 consisted of 112 age- and sex-matched healthy controls (mean age: 9±4.7 years). Serum ferritin level was 2487±1103 (range: 661-5745) ng/mL in Group 1. In comparing the correlation between ferritin and lipid parameters, while a significantly negative relationship was detected between ferritin and highdensity lipoprotein cholesterol (HDL-C) (p=0.000, r=-0.602), a significantly positive relationship was detected between ferritin and triglyceride (TG) levels (p=0.02) in TM patients. Serum lipid profiles of the 3 groups are shown in Table 1