Juan Carlos Cuevas

Juan Carlos Cuevas
Universidad Autónoma de Madrid | UAM · Department of Condensed Matter Physics

PhD

About

177
Publications
19,735
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
10,900
Citations
Citations since 2016
58 Research Items
5919 Citations
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
Introduction
I am a theoretical physicist working on the description of the transport, heat, mechanical and optical properties of a wide variety of nanostructures. In particular, my research has been focused on the study of the electronic transport in atomic-scale systems and superconducting nanostructures.
Additional affiliations
October 2004 - present
Universidad Autónoma de Madrid
Description
  • Associate professor
November 2003 - December 2007
Karlsruhe Institute of Technology
Position
  • Junior research group leader
Description
  • Leader of the Nachwuchsgruppe on Theoretical Aspects of Molecular electronics.
November 1999 - November 2003
Karlsruhe Institute of Technology
Position
  • PostDoc Position
Description
  • Post-doctoral researcher
Education
October 1988 - June 1993
Universidad Autónoma de Madrid
Field of study
  • Physics

Publications

Publications (177)
Preprint
We present here a theoretical method to determine the phononic contribution to the thermal conductance of nanoscale systems in the phase-coherent regime. Our approach makes use of classical molecular dynamics (MD) simulations to calculate the temperature-dependent dynamical matrix, and the phononic heat conductance is subsequently computed within t...
Article
Full-text available
A single spin in a Josephson junction can reverse the flow of the supercurrent by changing the sign of the superconducting phase difference across it. At mesoscopic length scales, these π-junctions are employed in various applications, such as finding the pairing symmetry of the underlying superconductor, as well as quantum computing. At the atomic...
Article
Full-text available
Azurin proteins are the workhorse of protein electronics. This is a branch of biomolecular electronics, a recent research field which investigates electronics based on biomolecules such as proteins, peptides, amino acids, bacterial nanowires or DNA. In general, the possibility of including biosystems in solid-state junctions has opened the way to t...
Preprint
Transport through quantum coherent conductors, like atomic junctions, is described by the distribution of conduction channels. Information about the number of channels and their transmission can be extracted from various sources, such as multiple Andreev reflections, dynamical Coulomb blockade, or shot noise. We complement this set of methods by in...
Article
Full-text available
Magnetic impurities on superconductors induce discrete bound levels inside the superconducting gap, known as Yu-Shiba-Rusinov (YSR) states. YSR levels are fully spin polarized such that the tunneling between YSR states depends on their relative spin orientation. Here, we use scanning tunneling spectroscopy to resolve the spin dynamics in the tunnel...
Article
Full-text available
We studied the coherent electron transport through metal–protein–metal junctions based on a blue copper azurin, in which the copper ion was replaced by three different metal ions (Co, Ni and Zn). Our results show that neither the protein structure nor the transmission at the Fermi level change significantly upon metal replacement. The discrepancy w...
Preprint
Magnetic impurities on superconductors induce discrete bound levels inside the superconducting gap, known as Yu-Shiba-Rusinov (YSR) states. YSR levels are fully spin-polarized such that the tunneling between YSR states depends on their relative spin orientation. Here, we use scanning tunneling spectroscopy to resolve the spin dynamics in the tunnel...
Article
Full-text available
There is a limit to the miniaturization of every process, and for charge transport this is realized by the coupling of two single discrete energy levels at the atomic scale. In superconductors, Yu–Shiba–Rusinov (YSR) states are such levels. Here, we place a magnetic impurity on the tip of a scanning tunnelling microscope (YSR-STM) and use it to dem...
Article
Full-text available
Spin-dependent scattering from magnetic impurities inside a superconductor gives rise to Yu-Shiba-Rusinov (YSR) states within the superconducting gap. They can be modeled by the largely equivalent Kondo or Anderson impurity models. The role of the magnetic and nonmagnetic properties of the impurity in relation to the coupling to the substrate is st...
Article
Full-text available
Understanding charge transport in DNA molecules is a long-standing problem of fundamental importance across disciplines1,2. It is also of great technological interest due to DNA’s ability to form versatile and complex programmable structures. Charge transport in DNA-based junctions has been reported using a wide variety of set-ups2–4, but experimen...
Preprint
Multiterminal Josephson junctions constitute engineered topological systems in arbitrary synthetic dimensions defined by the superconducting phases. Microwave spectroscopy enables the measurement of the quantum geometric tensor, a fundamental quantity describing both the quantum geometry and the topology of the emergent Andreev bound states in a un...
Article
There is a limit to the miniaturization of every process, and for charge transport this is realized by the coupling of two single discrete energy levels at the atomic scale. In superconductors, Yu–Shiba–Rusinov (YSR) states are such levels. Here, we place a magnetic impurity on the tip of a scanning tunnelling microscope (YSR-STM) and use it to dem...
Article
Full-text available
The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of a superconductor on a local scale. We use atomic manipulation in a low temperature STM to create mesoscopic single channel contacts and study the Josephson effect at arbitrary transmissions. We observe significant deviations from the Ambegaok...
Preprint
Motivated by recent scanning tunneling microscopy experiments on single magnetic impurities on superconducting surfaces, we present here a comprehensive theoretical study of the interplay between Yu-Shiba-Rusinov bound states and (multiple) Andreev reflections. Our theory is based on a combination of an Anderson model with broken spin degeneracy an...
Article
Full-text available
As scanning tunneling microscopy is pushed towards fast local dynamics, a quantitative understanding of tunnel junctions under the influence of a fast ac driving signal is required, especially at the ultralow temperatures relevant to spin dynamics and correlated electron states. We subject a superconductor-insulator-superconductor junction to a mic...
Article
Full-text available
Quantum fluctuations are imprinted with valuable information about transport processes. Experimental access to this information is possible, but challenging. We introduce the dynamical Coulomb blockade (DCB) as a local probe for fluctuations in a scanning tunneling microscope (STM) and show that it provides information about the conduction channels...
Preprint
As scanning tunneling microscopy is pushed towards fast local dynamics, a quantitative understanding of tunnel junctions under the influence of a fast AC driving signal is required, especially at the ultra-low temperatures relevant to spin dynamics and correlated electron states. We subject a superconductor-insulator-superconductor junction to a mi...
Preprint
Despite plenty of room at the bottom, there is a limit to the miniaturization of every process. For charge transport this is realized by the coupling of single discrete energy levels at the atomic scale. Here, we demonstrate sequential tunneling between parity protected Yu-Shiba-Rusinov (YSR) states bound to magnetic impurities located on the super...
Preprint
Spin-dependent scattering from magnetic impurities inside a superconductor gives rise to Yu-Shiba-Rusinov (YSR) states within the superconducting gap. As such, YSR states have been very successfully modeled with an effective scattering potential (Kondo impurity model). Using a scanning tunneling microscope, we exploit the proximity of the tip to a...
Preprint
Quantum fluctuations are imprinted with valuable information about transport processes. Experimental access to this information is possible, but challenging. We introduce the dynamical Coulomb blockade (DCB) as a local probe for fluctuations in a scanning tunneling microscope (STM) and show that it provides information about the conduction channels...
Article
Full-text available
Protein-based electronics is an emerging field which has attracted considerable attention over the past decade. Here, we present a theoretical study of the formation and electronic structure of a metal-protein-metal junction based on the blue-copper azurin from pseudomonas aeruginosa. We focus on the case in which the protein is adsorbed on a gold...
Article
A cytochrome C monolayer, attached to a gold layer and coated with a gold nanowire, can behave as an electrically driven switch, as reported by D. Cahen et al. in their Communication (DOI: 10.1002/anie.201906032). The charge‐transport mechanism of cytochrome C can be switched between on‐ and off‐resonant tunneling by varying the applied voltage bia...
Article
Eine Monolage aus Cytochrom C, die an eine Goldschicht gebunden und mit einem Goldnanodraht überzogen ist, kann sich wie ein elektrisch betriebener Schalter verhalten, wie D. Cahen et al. in ihrer Zuschrift berichten (DOI: 10.1002/ange.201906032). Der Ladungstransportmechanismus von Cytochrom C kann, selbst bei Raumtemperatur, durch Ändern der ange...
Article
A sample type protein monolayer, that can be a stepping stone to practical devices, can behave as an electrically‐driven switch. This feat is achieved using a redox protein, Cytochrome C, with its heme shielded from direct contact with the solid‐state electrodes. Ab initio DFT calculations, carried out on the whole CytC‐on‐Au structure, show that c...
Article
Full-text available
A sample type protein monolayer, that can be a stepping stone to practical devices, can behave as an electrically‐driven switch. This feat is achieved using a redox protein, Cytochrome C, with its heme shielded from direct contact with the solid‐state electrodes. Ab initio DFT calculations, carried out on the whole CytC‐on‐Au structure, show that c...
Article
Motivated by a recent experiment [C. Guo et al., Proc. Natl. Acad. Sci. U. S. A. 113, 10785 (2016)], we carry out a theoretical study of electron transport through peptide-based single-molecule junctions. We analyze the pristine hepta-alanine and its functionalizations with a single tryptophan unit, which is placed in three different locations alon...
Article
We predict here that a slab made of a doped semiconductor can exhibit anomalous refraction under the application of a static magnetic field. This anomalous refraction takes place in the far-infrared range and it occurs for any angle of incidence. We show that this effect is due to the fact that a doped semiconductor under a magnetic field can behav...
Article
Full-text available
We present a theoretical study of the blue-copper azurin extracted from Pseudomonas aeruginosa and several of its single amino acid mutants. For the first time, we consider the whole structure of this kind of protein rather than limiting our analysis to the copper complex only. This is accomplished by combining fully ab-initio calculations based on...
Preprint
We predict here that a slab made of a doped semiconductor can exhibit anomalous refraction under the application of a static magnetic field. This anomalous refraction takes place in the far-infrared range and it occurs for any angle of incidence. We show that this effect is due to the fact that a doped semiconductor under a magnetic field can behav...
Preprint
Topology is providing new insight into condensed matter physics problems. Concepts like Chern numbers and their relation to physical phenomena have become very familiar, but actually, key quantities like the quantum geometric tensor, which provides a much deeper information about quantum states, remain experimentally difficult to access. Recently i...
Preprint
The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of the superconducting order parameter on a local scale through the Ambegaokar-Baratoff (AB) relation. Using single atomic contacts created by means of atom manipulation, we demonstrate that in the extreme case of a single transport channel thro...
Article
Thermal radiation is one of the most universal physical phenomena and its study has played a key role in the history of modern physics. Our understanding of this subject has been traditionally based on Planck's law, which in particular sets limits on the amount of thermal radiation that can be emitted or exchanged. However, recent advances in the f...
Article
Full-text available
Motivated by recent experiments, we performed a theoretical study of electron transport through single-molecule junctions incorporating four kinds of homopeptides (based on alanine, glutamic acid, lysine, and tryptophan). Our results suggest that these molecules are rather insulating and operate in off-resonance tunneling as their main transport me...
Poster
Full-text available
The event is free of charge (up to 100 participants) thanks to support from CECAM and Psi-K. The focus of the conference will be the electron transport through biosystems, including proteins, peptides, DNA and bacterial nanowires. More details can be found on https://www.cecam.org/workshop-0-1522.html
Article
Very recently it has been predicted that the far-field radiative heat transfer between two macroscopic systems can largely overcome the limit set by Planck's law if one of their dimensions becomes much smaller than the thermal wavelength ($\lambda_{\rm Th} \approx 10\, \mu$m at room temperature). To explore the ultimate limit of the far-field viola...
Article
Full-text available
The study of thermoelectricity in molecular junctions is of fundamental interest for the development of various technologies including cooling (refrigeration) and heat-to-electricity conversion 1-4 . Recent experimental progress in probing the thermopower (Seebeck effect) of molecular junctions 5-9 has enabled studies of the relationship between th...
Article
We present a procedure to determine transmission eigenchannels for coherent phonon transport in nanoscale devices using the framework of nonequilibrium Green's functions. We illustrate our procedure by analyzing a one-dimensional chain, where all steps can be carried out analytically. More importantly, we show how the procedure can be combined with...
Article
Bioelectronics moves towards designing nanoscale electronic platforms that allow in vivo determinations. Such devices require interfacing complex biomolecular moieties as the sensing units to an electronic platform for signal transduction. Inevitably, a systematic design goes through a bottom-up understanding of the structurally related electrical...
Article
We predict a huge anisotropic thermal magnetoresistance (ATMR) in the near-field radiative heat transfer between magneto-optical particles when the direction of an external magnetic field is changed with respect to the heat current direction. We illustrate this effect with the case of two InSb spherical particles where we find that the ATMR amplitu...
Article
Motivated by recent experiments [Science 355, 6330 (2017); Nat. Nanotechnol. 12, 430 (2017)], we present here an extensive theoretical analysis of the thermal conductance of atomic-size contacts made of three different metals, namely gold (Au), platinum (Pt) and aluminum (Al).
Article
Full-text available
We present here a theoretical analysis that demonstrates that the far-field radiative heat transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field radiative heat transfer, we make use of the theory of fluctuational electro...
Article
We present an \emph{ab initio} study of the role of interference effects in the thermal conductance of single-molecule junctions. To be precise, using a first-principles transport method based on density functional theory, we analyze the coherent phonon transport in single-molecule junctions based on several benzene and oligo-phenylene-ethynylene d...
Article
Motivated by recent experiments, we present here an ab initio study of the impact of the phonon transport on the thermal conductance and thermoelectric figure of merit of C$_{60}$-based single-molecule junctions. To be precise, we combine density functional theory with nonequilibrium Green's function techniques to compute these two quantities in ju...
Article
Calorimetry reaches an atomic junction Electrical and thermal conductivity in metals are linked at the macroscopic length scale because electrons carry both heat and current. Cui et al. found that this relationship, the Wiedemann-Franz law, holds down to the atomic scale in gold and platinum (see the Perspective by Segal). They made thermal and ele...
Article
Full-text available
Radiative heat transfer in Ångström-and nanometre-sized gaps is of great interest because of both its technological importance and open questions regarding the physics of energy transfer in this regime. Here we report studies of radiative heat transfer in few Å to 5 nm gap sizes, performed under ultrahigh vacuum conditions between a Au-coated probe...
Data
Supplementary Figures, Supplementary Notes and Supplementary References.
Article
We present here a generalization of the thermal discrete dipole approximation (TDDA) that allows us to describe the near-field radiative heat transfer between finite objects of arbitrary shape that exhibit magneto-optical (MO) activity. We also extend the TDDA approach to describe the thermal emission of a finite object with and without MO activity...
Article
We demonstrate in this work that the use of metasurfaces provides a viable strategy to largely tune and enhance near-field radiative heat transfer between extended structures. In particular, using a rigorous coupled wave analysis, we predict that Si-based metasurfaces featuring two-dimensional periodic arrays of holes can exhibit a room-temperature...
Article
Motivated by recent experiments, we present here a systematic ab-initio study of the length dependence of the thermal conductance of single-molecule junctions. We make use of a combination of density functional theory with non-equilibrium Green's function techniques to investigate the length dependence of the phonon transport in single alkane chain...
Conference Paper
Radiative transfer of energy at the nanometer length scale is of great importance to a variety of technologies including heat-assisted magnetic recording, near-field thermophotovoltaics and lithography [1]. Although experimental advances have enabled elucidation of near-field radiative heat transfer in gaps as small as 20–30 nanometers, quantitativ...
Article
Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling micr...
Article
We present here a theoretical study that shows how the use of hybrid magnetoplasmonic crystals comprising both ferromagnetic and noble metals leads to a large enhancement of the performance of nanohole arrays as plasmonic sensors. In particular, we propose using Au-Co-Au films perforated with a periodic array of subwavelength holes as transducers i...
Article
Full-text available
Magnetoplasmonic crystals are spatially periodic nanostructured magnetic surfaces combining the features of surface plasmon polariton excitation and magneto-optical tunability. Here we present a comprehensive experimental and theoretical work demonstrating that in magnetoplasmonic crystals the coupling of free space radiation to surface plasmon pol...
Article
Full-text available
With the goal to elucidate the nature of spin-dependent electronic transport in ferromagnetic atomic contacts, we present here a combined experimental and theoretical study of the conductance and shot noise of metallic atomic contacts made of the 3d ferromagnetic materials Fe, Co, and Ni. For comparison, we also present the corresponding results fo...
Article
Full-text available
We present a theoretical study of the Faraday effect in hybrid magneto-plasmonic crystals that consist of Au-Co-Au perforated membranes with a periodic array of sub-wavelength holes. We show that in these hybrid systems the interplay between the extraordinary optical transmission and the magneto-optical activity leads to a resonant enhancement of t...
Article
Full-text available
We demonstrate large rectification ratios (> 100) in single-molecule junctions based on a metal-oxide cluster (polyoxometalate), using a scanning tunneling microscope (STM) both at ambient conditions and at low temperature. These rectification ratios are the largest ever observed in a single-molecule junction, and in addition these junctions sustai...
Article
Full-text available
We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathia-fulvalene (exTTF) group and its charge-transfer complex with F 4 TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conduc...
Article
We present a comprehensive theoretical study of the magnetic field dependence of the near-field radiative heat transfer (NFRHT) between two parallel plates. We show that when the plates are made of doped semiconductors, the near-field thermal radiation can be severely affected by the application of a static magnetic field. We find that irrespective...
Article
A combined experimental and theoretical study of the magneto-optic properties of a series of nickel antidot thin films is presented. The hole diameter varies from 869 down to 636 nm, while the lattice periodicity is fixed at 920 nm. This results in an overall increase of the polar Kerr rotation with decreasing hole diameter due to the increasing su...
Article
Thermal radiative emission from a hot surface to a cold surface plays an important role in many applications, including energy conversion, thermal management, lithography, data storage and thermal microscopy. Recent studies on bulk materials have confirmed long-standing theoretical predictions indicating that when the gap between the surfaces is re...
Article
Full-text available
Superconducting correlations may propagate between two superconductors separated by a tiny insulating or metallic barrier, allowing a dissipationless electric current to flow. In the presence of a magnetic field, the maximum supercurrent oscillates and each oscillation corresponding to the entry of one Josephson vortex into the barrier. Josephson v...
Article
We report conductance and thermopower measurements of metallic atomic-size contacts, namely gold and platinum, using a scanning tunneling microscope (STM) at room temperature. We find that few-atom gold contacts have an average negative thermopower, whereas platinum contacts present a positive thermopower, showing that for both metals, the sign of...
Article
Full-text available
DNA and DNA-based polymers are of interest in molecular electronics because of their versatile and programmable structures. However, transport measurements have produced a range of seemingly contradictory results due to differences in the measured molecules and experimental set-ups, and transporting significant current through individual DNA-based...
Article
Full-text available
It has been shown that a slab of a negative index material can behave as a superlens enhancing the imaging resolution beyond the wavelength limit. We show here that if such a slab possesses in addition some magneto-optical activity, it could act as an ideal optical filter and exhibit an extraordinary transverse magneto-optical Kerr effect. Moreover...
Article
Full-text available
Atomic-scale junctions are a powerful tool to study quantum transport, and are frequently examined through the mechanically controllable break junction technique (MCBJ). The junction-to-junction variation of atomic configurations often leads to a statistical approach, with ensemble-averaged properties providing access to the relevant physics. Howev...
Article
Full-text available
We present here an exhaustive ab initio study of the use of carbon-based tips as electrodes in single-molecule junctions. Motivated by recent experiments, we show that carbon tips can be combined with other carbon nanostructures, such as graphene, to form all-carbon molecular junctions with molecules like benzene or C60. Our results show that the u...