# Lucas J. Fernández-AlcázarNational Scientific and Technical Research Council | conicet · IMIT Instituto de Modelado e Innovación Tecnológica

Lucas J. Fernández-Alcázar

Ph.D. in Physics - University of Cordoba - Argentina

Assistant Researcher at the Institute of Modelling and Innovation on Technology
CONICET (Argentina)

## About

25

Publications

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162

Citations

Introduction

I'm Lucas J. Fernández-Alcázar, Assistant Researcher at CONICET in Corrientes, Argentina. My research interest lies in the interface between Photonics and Optics, Condensed Matter, and Quantum Mechanics. Specifically, I'm interested in the transport of wavelike excitations (electrons, photons, phonons, etc. ) in the micro and nanoscale in complex systems.

Additional affiliations

Education

April 2011 - March 2016

March 2006 - March 2011

## Publications

Publications (25)

We control the direction and magnitude of thermal radiation, between two bodies at equal temperature (in thermal equilibrium), by invoking the concept of adiabatic pumping. Specifically, within a resonant near-field electromagnetic heat transfer framework, we utilize an {\it instantaneous} scattering matrix approach to unveil the critical role of w...

We investigate the collective dynamics of nonlinearly interacting modes in multimode photonic settings. To this end, we have established a connection with the theory of spin networks. The emerging “photonic spins” are complex, soft (their size is not fixed), and their dynamics has two constants of motion. Our analysis sheds light on the nature of t...

Exceptional point degeneracies, occurring in non-Hermitian systems, have challenged many well established concepts and led to the development of remarkable technologies. Here, we propose a family of autonomous motors whose operational principle relies on exceptional points via the opportune implementation of a (pseudo-)PT-symmetry and its spontaneo...

We develop, within a near-field thermal radiation framework, a Floquet scattering approach that establishes a reconfigurable control of the direction of thermal radiation between reservoirs. The method promotes a connection with Floquet engineering -- originally developed in many-body physics -- thus allowing us to design periodically driven photon...

Decoherent transport in mesoscopic and nanoscopic systems can be formulated in terms of the D'Amato–Pastawski (DP) model. This generalizes the Landauer–Büttiker picture by considering a distribution of local decoherent processes. However, its generalization for multi-terminal set-ups is lacking. We first review the original two-terminal DP model fo...

We show analytically that the molecular dissociation occurring in a Heyrovsky reaction can be interpreted as a Quantum Dynamical Phase Transition, i.e. an analytical discontinuity in the molecular energy spectrum. Through appropriate election of the molecular orbital basis, it is shown that the metallic substrate plays the role of an environment th...

Through an appropriate election of the molecular orbital basis, we show analytically that the molecular dissociation occurring in a Heyrovsky reaction can be interpreted as a Quantum Dynamical Phase Transition, i.e., an analytical discontinuity in the molecular energy spectrum induced by the catalyst. The metallic substrate plays the role of an env...

We numerically implement the concept of thermal radiation pumps in realistic photonic circuits and demonstrate their efficiency to control the radiation current, emitted between two reservoirs with equal temperature. The proposed pumping scheme involves a cyclic adiabatic modulation of two parameters that control the spectral characteristics of the...

A stationary inflection point (SIP) of the Bloch dispersion relation of a periodic system is a prominent example of an exceptional point degeneracy (EPD) where three Bloch eigenmodes coalesce. The scattering problem for a bounded photonic structure supporting a SIP features the frozen mode regime (FMR), where the incident wave is converted into the...

By using Floquet driving protocols and interlacing them with a judicious reservoir emission engineering, we achieve extreme nonreciprocal thermal radiation. We show that the latter is rooted in an interplay between a direct radiation process occurring due to temperature bias between two thermal baths and the modulation process that is responsible f...

In recent years, there has been an increasing interest in nanoelectromechanical devices, current-driven quantum machines, and the mechanical effects of electric currents on nanoscale conductors. Here, we carry out a thorough study of the current-induced forces and the electronic friction of systems whose electronic effective Hamiltonian can be desc...

In recent years, there has been an increasing interest in nanoelectromechanical devices, current-driven quantum machines, and the mechanical effects of electric currents on nanoscale conductors. Here, we carry out a thorough study of the current-induced forces and the electronic friction of systems whose electronic effective Hamiltonian can be desc...

A thermal current, generated by a temperature gradient between two reservoirs coupled to a carefully designed photonic or (micro-) electromechanical circuit, might induce non-conservative forces that impulse a mechanical degree of freedom to move along a closed trajectory. We show that in the limit of long - but finite - modulation periods, the ext...

Scattering processes are typically sensitive to the incident wave properties and to interference effects generated via wave-matter interactions with the target. We challenge this general belief in the case of targets that undergo time-periodic modulations encircling quasiadiabatically an exceptional point in a given parameter space. When the scatte...

We control the direction and magnitude of thermal radiation, between two bodies at equal temperature (in thermal equilibrium), by invoking the concept of adiabatic pumping. Specifically, within a resonant near-field electromagnetic heat transfer framework, we utilize an instantaneous scattering matrix approach to unveil the critical role of wave in...

In recent years, there has been an increasing interest in nanomachines. Among them, current-driven ones deserve special attention as quantum effects can play a significant role there. Examples of the latter are the so-called adiabatic quantum motors. In this paper, we propose using Anderson's localization to induce nonequilibrium forces in adiabati...

In recent years there has been an increasing interest in nanomachines. Among them, current-driven ones deserve special attention as quantum effects can play a significant role there. Examples of the latter are the so-called adiabatic quantum motors. In this work, we propose using Anderson's localization to induce nonequilibrium forces in adiabatic...

Different proposals for adiabatic quantum motors (AQMs) driven by DC currents have recently attracted considerable interest. However, the systems studied are often based on simplified models with highly ideal conditions where the environment is neglected. Here, we investigate the performance (dynamics, efficiency, and output power) of a prototypica...

Current induced forces are not only related with the discrete nature of electrons but also with its quantum character. It is natural then to wonder about the effect of decoherence. Here, we develop the theory of current induced forces including dephasing processes and we apply it to study adiabatic quantum motors (AQMs). The theory is based on B\"u...

We present a model for decoherence in time-dependent transport. It boils down
into a form of wave function that undergoes a smooth stochastic drift of the
phase in a local basis, the Quantum Drift (QD) model. This drift is nothing
else but a local energy fluctuation. Unlike Quantum Jumps (QJ) models, no jumps
are present in the density as the evolu...

We describe the spin-dependent quantum conductance in a wire where a magnetic field is spatially modulated. The change in direction and intensity of the magnetic field acts as a perturbation that mixes spin projections. This is exemplified by a ferromagnetic nanowire. There the local field varies smoothly its direction generating a domain wall (DW)...

Decoherent transport in mesoscopic and nanoscopic systems can be formulated
in terms of the D'Amato-Pastawski (DP) model. This generalizes the
Landauer-B\"{u}ttiker picture by considering a distribution of decoherent local
scattering centers of decoherence. However, its generalization for
multiterminal setups is lacking. We first review the origina...

We address the spin-dependent electronic transport through regions where
there is a spatially modulated magnetic field. We model and solve an
illustrative example: a ferromagnetic nano-wire with a single domain wall (DW)
whose finite width where the local field rotates while it modifies its
intensity. There is a trivial case where the electrons whi...

## Projects

Projects (3)

In this project, we study the phenomena arising from the coupling between a flux of quantum particles and a classical degree of freedom. In particular, we focus on current-induced forces, electronic friction, quantum pumping, and geometric rectification. We study those phenomena from a fundamental point of view but also seeking new proposals for nanodevices such as nanomotors or nanoscale energy harvesters.