Periodic Energy Transport and Entropy Production in Quantum Electronics

The problem of time-dependent particle transport in quantum conductors is nowadays a well established topic. In contrast, the way in which energy and heat flow in mesoscopic systems subjected to dynamical drivings is a relatively new subject that cross-fertilize both fundamental developments of quantum thermodynamics and practical applications in nanoelectronics and quantum information. In this short review, we discuss from a thermodynamical perspective recent investigations on nonstationary heat and work generated in quantum systems, emphasizing open questions and unsolved issues.Fil: Ludovico, María Florencia. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; ArgentinaFil: Arrachea, Liliana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; ArgentinaFil: Moskalets, Michael. Kharkiv Polytechnic Institute; UcraniaFil: Sánchez, David. Consejo Superior de Investigaciones Científicas; Españ

Effective tunneling processes in an interferometer of helical edge states with an antidot

We consider an interferometer of edge states of a two-dimensional topological insulator with an antidot. We analyze the mechanisms leading to an effective tunneling with spin flip between different helical states.Fil: Rizzo, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Camjayi, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Arrachea, Liliana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Work exchange, geometric magnetization, and fluctuation-dissipation relations in a quantum dot under adiabatic magnetoelectric driving

We study the adiabatic dynamics of the charge, spin, and energy of a quantum dot with a Coulomb interaction under two-parameter driving, associated to time-dependent gate voltage and magnetic field. The quantum dot is coupled to a single reservoir at temperature T=0 and the dynamical Onsager matrix is fully symmetric, hence, the net energy dynamics is fully dissipative. However, in the presence of many-body interactions, other interesting mechanisms take place, like the net exchange of work between the two types of forces and the nonequilibrium accumulation of charge with different spin orientations. The latter has a geometric nature. The dissipation takes place in the form of an instantaneous Joule law with the universal resistance R0=h/2e2. We show the relation between this Joule law and instantaneous fluctuation-dissipation relations. The latter lead to generalized Korringa-Shiba relations, valid in the Fermi-liquid regime.Fil: Terren Alonso, Pablo Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Romero, Javier. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Arrachea, Liliana del Carmen. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Enhanced thermoelectric response in the fractional quantum Hall effect

We study the linear thermoelectric response of a quantum dot embedded in a constriction of a quantum Hall bar with fractional filling factors ν=1/m within Laughlin series. We calculate the figure of merit ZT for the maximum efficiency at a fixed temperature difference. We find a significant enhancement of this quantity in the fractional filling in relation to the integer-filling case, which is a direct consequence of the fractionalization of the electron in the fractional quantum Hall state. We present simple theoretical expressions for the Onsager coefficients at low temperatures, which explicitly show that ZT and the Seebeck coefficient increase with m.Fil: Roura Bas, Pablo Gines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Arrachea, Liliana del Carmen. Freie Universität Berlin; Alemania. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fradkin, Eduardo. University of Illinois at Urbana; Estados Unido

Helical spin thermoelectrics controlled by a side-coupled magnetic quantum dot in the quantum spin Hall state

We study the thermoelectric response of a device containing a pair of helical edge states contacted at thesame temperature T and chemical potential μ and connected to an external reservoir, with different chemicalpotential and temperature, through a side quantum dot. Different operational modes can be induced by applyinga magnetic field B and a gate voltage Vg at the quantum dot. At finite B, the quantum dot acts simultaneously asa charge and a spin filter. Charge and spin currents are induced, not only through the quantum dot, but also alongthe edge states. We focus on linear response and analyze the regimes, which we identify as charge heat enginesor refrigerator, spin heat engine, and spin refrigerator.Fil: Roura Bas, Pablo Gines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Arrachea, Liliana del Carmen. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Kavli Institute for Theoretical Physics; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fradkin, Eduardo. University of Illinois at Urbana; Estados Unido

Nonlocal thermoelectric engines in hybrid topological Josephson junctions

The thermoelectric performance of a topological Josephson nonlocal heat engine is thoroughly investigated. The nonlocal response is obtained by using a normal metal probe coupled to only one of the proximized helical edges in the middle of the junction. In this configuration, we investigate how the flux and phase biases trigger the nonlocal thermoelectric effects under the application of a thermal difference between the superconducting terminals. Possible experimental nonidealities such as asymmetric proximized superconducting gaps are considered, showing how the nonlocal response can be affected. The interplay between Doppler shift, which tends to close gaps, and Andreev interferometry, which affects particle-hole resonant transport, are clearly identified for different operating regimes. Finally, we discuss the power and the efficiency of the topological thermoelectric engine which reaches maximum power at maximal efficiency for a well-coupled normal probe. We find quite high nonlocal Seebeck coefficients of the order of tenths of μV/K at a few Kelvin, a signal that would also be clearly detectable against any spurious local effects even with moderate asymmetry of the gaps.Fil: Blasi, Gianmichele. Consiglio Nazionale delle Ricerche; ItaliaFil: Taddei, Fabio. Consiglio Nazionale delle Ricerche; ItaliaFil: Arrachea, Liliana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; ArgentinaFil: Carrega, Matteo. Consiglio Nazionale delle Ricerche; ItaliaFil: Braggio, Alessandro. Consiglio Nazionale delle Ricerche; Itali

Proximity induced time-reversal topological superconductivity in Bi2Se3 films without phase tuning

Many proposals to generate a time-reversal invariant topological superconducting phase are based on imposing a π phase difference between the superconducting leads proximitizing a nanostructure. We show that this phase can be induced on a thin film of a topological insulator like Bi2Se3 in proximity to a single s-wave superconductor. In our analysis we take into account the parity degree of freedom of the electronic states which is not included in effective Dirac-like surface theories. We find that the topological phase can be reached when the induced interparity pairing dominates over the intraparity one. Application of an electric field perpendicular to the film extends the range of parameters where the topological phase occurs.Fil: Casas, Oscar E.. Universidad Nacional de Colombia; Colombia. Universidad Autónoma de Madrid; EspañaFil: Arrachea, Liliana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Herrera, William J.. Universidad Nacional de Colombia; ColombiaFil: Levy Yeyati, Alfredo. Universidad Autónoma de Madrid; Españ

Nonlinear charge and energy dynamics of an adiabatically driven interacting quantum dot

We formulate a general theory to study the time-dependent charge and energy transport of an adiabatically driven interacting quantum dot in contact with a reservoir for arbitrary amplitudes of the driving potential. We study within this framework the Anderson impurity model with a local ac gate voltage. We show that the exact adiabatic quantum dynamics of this system is fully determined by the behavior of the charge susceptibility of the frozen problem. At T=0, we evaluate the dynamic response functions with the numerical renormalization group (NRG). The time-resolved heat production exhibits a pronounced feature described by an instantaneous Joule law characterized by a universal Büttiker resistance quantum R0=h/(2e2) for each spin channel. We show that this law holds in the noninteracting as well as in the interacting system and also when the system is spin polarized. In addition, in the presence of a static magnetic field, the interplay between many-body interactions and spin polarization leads to a nontrivial energy exchange between electrons with different spin components.Fil: Romero, Javier I.. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Roura Bas, Pablo Gines. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aligia, Armando Ángel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Arrachea, Liliana del Carmen. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Heat current across a capacitively coupled double quantum dot

We study the heat current through two capacitively coupled quantum dots coupled in series with two conducting leads at different temperatures T L and T R in the spinless case (valid for a high applied magnetic field). Our results are also valid for the heat current through a single quantum dot with strongly ferromagnetic leads pointing in opposite directions (so that the electrons with given spin at the dot can jump only to one lead) or through a quantum dot with two degenerate levels with destructive quantum interference and high magnetic field. Although the charge current is always zero, the heat current is finite when the interdot Coulomb repulsion U is taken into account due to many-body effects. We study the thermal conductance as a function of temperature and the dependence of the thermal current with the couplings to the leads, T L − T R , energy levels of the dots and U , including conditions for which an orbital Kondo regime takes place. When the energy levels of the dots are different, the device has rectifying properties for the thermal current. We find that the ratio between the thermal current resulting from a thermal bias T L > T R and the one from T L < T R is maximized for particular values of the energy levels, one above and the other below the Fermi level.Fil: Aligia, Armando Angel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Perez Daroca, Diego Raul. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arrachea, Liliana del Carmen. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roura Bas, Pablo Gines. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Thermoelectricity in Quantum Hall Corbino Structures

We measure the thermoelectric response of Corbino structures in the quantum Hall effect regime and compare it with a theoretical analysis. The measured thermoelectric voltages are qualitatively and quantitatively simulated based upon the independent measurement of the conductivity, indicating that they originate predominantly from the electron diffusion. In contrast to earlier Hall-bar experiments, electron-phonon interaction does not lead to a phonon-drag contribution. This implies a description of the Onsager coefficients on the basis of a single transmission function, from which both thermovoltage and conductivity can be predicted with a single fitting parameter. Furthermore, it lets us predict a figure of merit for the efficiency of thermoelectric cooling, which becomes very large for partially filled Landau levels and high magnetic fields.Fil: Real, Mariano. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Gresta, Daniel Matías. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reichl, Christian. Swiss Federal Institute of Technology Zurich; SuizaFil: Weis, Jürgen. Max Planck Institut für Festkörperforschung; AlemaniaFil: Tonina, Alejandra. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Giudici, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Constituyentes | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Constituyentes; ArgentinaFil: Arrachea, Liliana del Carmen. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wegscheider, Werner. Swiss Federal Institute of Technology Zurich; SuizaFil: Fluck, Werner Thomas. Max Planck Institut für Festkörperforschung; Alemani