The efficiency of a thermal engine working in linear response regime multi-terminals configuration is discussed. For the generic three-terminal case, we provide general definition local and non-local transport coefficients: electrical conductances, thermoelectric powers. Within Onsager formalism, derive analytical expressions for at maximum power, which can be written terms generalized figures merit. Also, using two examples, investigate numerically how third terminal could improve...

We study the thermoelectric properties and heat-to-work conversion performance of an interacting, multi-level quantum dot (QD) weakly coupled to electronic reservoirs. focus on sequential tunneling regime. The dynamics charge in QD is studied by means master equations for probabilities occupation. From here we compute heat currents linear response Assuming a generic multi-terminal setup, low temperatures (quantum limit), obtain analytical expressions transport coefficients which account...

We demonstrate high-temperature thermoelectric conversion in InAs/InP nanowire quantum dots by taking advantage of their strong electronic confinement. The electrical conductance G and the thermopower S are obtained from charge transport measurements accurately reproduced with a theoretical model accounting for multilevel structure dot. Notably, our analysis does not rely on estimate cotunnelling contributions, since thermal is dominated heat transport. By into account two spin-degenerate...

Despite topological protection and the absence of magnetic impurities, two-dimensional insulators display quantized conductance only in surprisingly short channels, which can be as 100 nm for atomically thin materials. We show that combined action short-range nonmagnetic impurities located near edges on site electron-electron interactions effectively creates noncollinear scatterers, and, hence, results strong backscattering. The mechanism causes deviations from quantization even at zero...

We analyze a simple implementation of an absorption refrigerator, system that requires heat and not work to achieve refrigeration, based on two Coulomb coupled single-electron systems. analytically determine the general condition cooling-by-heating, we parameters simultaneously maximize cooling power coefficient performance (COP) finding displays particularly COP can reach Carnot's upper limit. also find be indirectly determined by measuring charge current. Analyzing as autonomous Maxwell...

A quantum thermal machine can be controlled by time-periodic perturbations that define a cycle, as in conventional macroscopic machines. This paper presents general and unified approach to the study of machines, including both heat engines refrigerators, which operate under periodic adiabatic driving are contact with reservoirs kept at different temperatures. Importantly, many observables characterizing operation performance these machines geometric nature.

The dissociative reduction of a series symmetrical (RSSR, R = H, Me, t-Bu, Ph) and unsymmetrical disulfides (RSSR', R' Me Ph, t-Bu) was studied theoretically, by MO ab initio calculations and, for five them, also experimentally, convolution voltammetry in N,N-dimethylformamide. is but proceeds stepwise mechanism entailing the formation radical anion species. electrochemical data led to estimated large intrinsic barriers, agreement with an unusually structural modification undergone disulfide...

Spin currents can be obtained through adiabatic pumping by means of electrical gating only. This is possible making use the tunability Rashba spin-orbit coupling in semiconductor heterostructures. We demonstrate principles this effect considering a single-channel wire with constriction. also consider realistic structures, consisting several open channels where subband spin mixing and disorder are present, we confirm our predictions. Two different ways to detect spin-pumping effect, either...

The electron transfer (ET) to a series of para-substituted diaryl disulfides, having the general formula (X−C6H4S−)2, has been studied. X groups were selected as have comprehensive variation substituent effect, being = NH2, MeO, H, F, Cl, CO2Et, CN, and NO2. reduction was carried out experimentally, using N,N-dimethylformamide solvent, by molecular orbital (MO) ab initio calculations. ET studied heterogeneously, voltammetric convolution analysis, homogeneously, electrogenerated radical...

We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect bulk-graphene case. At subgap voltages, conservation of pseudoparity, quantum number characterizing ribbon states, yields either suppression when has an even sites transverse direction or perfect odd sites. In former case induces insulating behavior junction is biased;...

Folded graphene flakes are a natural byproduct of the micromechanical exfoliation process. In this article we show by combination analytical and numerical methods that such systems behave as intriguing interferometers due to interplay between an externally applied magnetic field gauge induced deformations in region fold.

In a multi-terminal device the (electronic) heat and charge currents can follow different paths. this paper we introduce analyse class of devices where property is pushed to its extreme limits, with $and$ flowing in reservoirs. After introducing main characteristics such $heat-charge$ $current$ $separation$ regime show how realise it normal superconducting leads. We demonstrate that allows control independently flows greatly enhance thermoelectric performances at low temperatures. details...

We experimentally realize protocols that allow us to extract work beyond the free energy difference from a single-electron transistor at single thermodynamic trajectory level. With two carefully designed out-of-equilibrium driving cycles featuring kicks of control parameter, we demonstrate extraction up large fractions kBT or with probabilities substantially greater than 1/2, despite zero over cycle. Our results are explained in framework nonequilibrium fluctuation relations. thus show...

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties twisted bilayer graphene (TBG) at different filling factors twist angles $\theta$. Our calculations are based on electronic band structures obtained from continuum model that has two tunable parameters, $u_0$ $u_1$, which parametrize intra-sublattice inter-layer inter-sublattice tunneling rate, respectively. In this Article we focus key aspects: i) dependence our results value...

We consider a Josephson junction hosting Kramers pair of helical edge states quantum spin Hall bar in contact with normal-metal probe. In this hybrid system, the orbital phase, induced by small magnetic field threading known as Doppler shift, combines conventional phase difference and originates an effect akin to Zeeman spectrum. As consequence, when temperature bias is applied superconducting terminals, thermoelectric current established normal argue that purely nonlocal unique signature...

We study heat rectification through quantum dots in the Coulomb blockade regime using a master equation approach. consider both cases of two-terminal and four-terminal devices. In configuration, we analyze case single dot with either doubly-degenerate level or two non-degenerate levels. sequential tunneling behaviour currents as functions position energy levels temperature bias. particular, derive an upper bound for closed-circuit setup level. also prove absence identify ideal system...

By evidencing the holonomic and dynamical contributions in scattering problems, we develop a method for calculating matrix of electrons one-dimensional coherent conductor connected to two electrodes. To validate our approach, investigate spin-resolved along wire subjected spatially varying magnetic (Zeeman) field. In particular, show that high-energy limit, transmission aligns with holonomy, reducing pure topological form. We illustrate by examining several scenarios varied in-plane field...

Spin-polarized transport is investigated in normal metal--superconductor (NS) junctions as a function of interface transmissivity well temperature when the density states superconductor Zeeman-split response to an exchange field $({h}_{\text{exc}})$. Similarly ``absolute spin-valve effect'' predicted by Huertas-Hernando et al. [Phys. Rev. Lett. 88, 047003 (2002)] superconducting proximity structures, we show that NS can be used generate highly spin-polarized currents, alternative...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic criteria for aromaticityRois Benassi, Paolo Lazzeretti, and Ferdinando TaddeiCite this: J. Phys. Chem. 1975, 79, 8, 848–851Publication Date (Print):April 1, 1975Publication History Published online1 May 2002Published inissue 1 April 1975https://pubs.acs.org/doi/10.1021/j100575a015https://doi.org/10.1021/j100575a015research-articleACS PublicationsRequest reuse permissionsArticle Views166Altmetric-Citations49LEARN ABOUT THESE METRICSArticle...

We introduce and experimentally demonstrate a new method that allows us to controllably couple copropagating spin-resolved edge states of two-dimensional electron gas (2DEG) in the integer quantum Hall regime. The scheme exploits spatially periodic in-plane magnetic field is created by an array Cobalt nanomagnets placed at boundary 2DEG. A maximum charge or spin transfer $28\ifmmode\pm\else\textpm\fi{}1%$ achieved 250 mK.

We study by means of the recursive Green's function technique local density-of-states (finite and semi-infinite) multi-band spin-orbit coupled semiconducting nanowires in proximity to an s-wave superconductor attached normal-metal electrodes. When nanowire is a normal electrode, zero-energy peak, corresponding Majorana state topological phase, broadens with increasing transmission between wire leads, eventually disappearing for ideal interfaces. Interestingly, finite peak present also even...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAcid-base behavior of sulfoxides. Measurement pKa values by ultraviolet and nuclear magnetic resonance techniquesD. Landini, Giorgio Modena, Gianfranco Scorrano, Ferdinando TaddeiCite this: J. Am. Chem. Soc. 1969, 91, 24, 6703–6707Publication Date (Print):November 1, 1969Publication History Published online1 May 2002Published inissue 1 November 1969https://pubs.acs.org/doi/10.1021/ja01052a028https://doi.org/10.1021/ja01052a028research-articleACS...

We present a comprehensive and systematic study of thermal rectification in prototypical low-dimensional quantum system---a nonlinear resonator: we identify necessary conditions to observe discuss strategies maximize it. focus, particular, on the case where anharmonicity is very strong system reduces qubit. In latter case, derive general upper bounds which hold weak system-bath coupling regime, show how Lamb shift can be exploited enhance rectification. then go beyond weak-coupling regime by...