Mesoscale and Nanoscale Physics

New submissions

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New submissions for Fri, 3 May 24

[1]  arXiv:2405.00759 [pdf, ps, other]

Title: Topological Corner Modes by Composite Wannier States in Glide-Symmetric Photonic Crystal

Authors: Zhenzhen Liu, Xiaoxi Zhou, Guochao Wei, Lei Gao, Bo hou, Jun-Jun Xiao

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Optics (physics.optics)

Second-order topological insulators can be characterized by their bulk polarization, which is believed to be intrinsically connected to the center of the Wannier function. In this study, we demonstrate the existence of second-order topological insulators that feature a pair of partially degenerate photonic bands. These arise from the nonsymmorphic glide symmetry in an all-dielectric photonic crystal. The center of the maximally localized Wannier function (MLWF) is consistently located at the origin but is not equivalent with respect to the sum of constituent polarizations. As a result, topological corner modes can be identified by the distinctly hybridized MLWFs that truncate at the sample boundary. Through full-wave numerical simulations paired with microwave experiments, the second-order topology is clearly confirmed and characterized. These topological corner states exhibit notably unique modal symmetries, which are made possible by the inversion of the Wannier bands. Our results provide an alternative approach to explore higher-order topological physics with significant potential for applications in integrated and quantum photonics.

[2]  arXiv:2405.00811 [pdf, other]

Title: Localized and extended phases in square moiré patterns

Authors: Christian Madroñero, Gustavo Alexis Dominguez Castro, Rosario Paredes

Comments: 9 pages, 9 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Gases (cond-mat.quant-gas)

Random defects do not constitute the unique source of electron localization in two dimensions. Lattice quasidisorder generated from two inplane superimposed rotated, main and secondary, square lattices, namely monolayers where moir\'e patterns are formed, leads to a sharp localized to delocalized single-particle transition. This is demostrated here for both, discrete and continuum models of moir\'e patterns that arise as the twisting angle $\theta$ between main and secondary lattices is varied in the interval $[0, \pi/4]$. Localized to delocalized transition is recognized as the moir\'e patterns depart from being perfect square crystals to non-crystalline structures. Extended single-particle states were found for rotation angles associated with Pythagorean triples that produce perfectly periodic structures. Conversely, angles not arising from such Pythagorean triples lead to non-commensurate or quasidisordered structures, thus originating localized states. These conclusions are drawn from a stationary analysis where the standard IPR parameter measuring localization allowed us to detect the transition. While both, ground state and excited states were analyzed for the discrete model, where the secondary lattice was considered as a perturbation of the main one, the sharp transition was tracked back for the fundamental state in the continuous scenario where the secondary lattice is not a perturbation any more.

[3]  arXiv:2405.00862 [pdf, other]

Title: Effects of Dzyaloshinskii-Moriya interactions and dipole-dipole interactions on spin waves in finite-length ferromagnetic chains

Authors: Bushra Hussain, Michael Cottam

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

A spin-wave theory that includes the antisymmetric Dzyaloshinskii-Moriya exchange interactions and long-range dipole-dipole interactions is presented for finite-length ferromagnetic spin chains. It is found that three different physical situations arise, depending on the direction chosen in this geometry for the axial vector of the Dzyaloshinskii-Moriya interactions. In some cases this leads to a tilting of the equilibrium orientations near the ends of the chain due to interfacial effects and with consequential effects on the spectrum of discrete dipole-exchange spin waves. When variations are introduced for the dominant bilinear exchange interactions at the ends of the spin chain, it is shown that localized spin waves with spatial decay characteristics may occur.

[4]  arXiv:2405.01075 [pdf, other]

Title: Non-equilibrium carrier dynamics and band structure of graphene on 2D tin

Authors: Maria-Elisabeth Federl, Niklas Witt, Biao Yang, Niklas Hofmann, Johannes Gradl, Leonard Weigl, Ignacio Piquero-Zulaica, Johannes V. Barth, Neeraj Mishra, Camilla Coletti, Tim O. Wehling, Isabella Gierz

Comments: 19 pages, 5 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

Intercalation of epitaxial graphene on SiC(0001) with Sn results in a well-ordered 2D metallic Sn phase with a $(1\times1)$ structure at the interface between SiC substrate and quasi-freestanding graphene. The 2D\,Sn phase exhibits exotic electronic properties with Dirac-like and flat bands coexisting close to the Fermi level that exhibit both Zeeman- and Rashba-type spin splittings. Possible inter-layer interactions between the 2D\,Sn layer and graphene that may result in emerging electronic properties remain unexplored. We use time- and angle-resolved photoemission spectroscopy to reveal a surprisingly short-lived non-equilibrium carrier distribution inside the Dirac cone of graphene. Further, we find that the graphene $\pi$-band exhibits a transient down-shift that we attribute to charging of the graphene layer with holes. We interpret our results with support from density functional theory calculations of the graphene - 2D\,Sn heterostructure that reveal a substantial hybridization between graphene $\pi$-band and Sn $p_z$-states that opens up a $\sim230$\,meV band gap inside the Dirac cone and delocalizes the charge carriers over both the graphene and 2D\,Sn layers. Our results have important implications for the design of future ultrafast optoelectronic devices that may find applications in the fields of light harvesting and detection, as supercapacitors, or in novel quantum computing technologies.

[5]  arXiv:2405.01240 [pdf, other]

Title: Machine-learned tuning of artificial Kitaev chains from tunneling-spectroscopy measurements

Authors: Jacob Benestad, Athanasios Tsintzis, Rubén Seoane Souto, Martin Leijnse, Evert van Nieuwenburg, Jeroen Danon

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We demonstrate reliable machine-learned tuning of quantum-dot-based artificial Kitaev chains to Majorana sweet spots, using the covariance matrix adaptation algorithm. We show that a loss function based on local tunnelling-spectroscopy features of a chain with two additional sensor dots added at its ends provides a reliable metric to navigate parameter space and find points where crossed Andreev reflection and elastic cotunneling between neighbouring sites balance in such a way to yield near-zero-energy modes with very high Majorana quality. We simulate tuning of two- and three-site Kitaev chains, where the loss function is found from calculating the low-energy spectrum of a model Hamiltonian that includes Coulomb interactions and finite Zeeman splitting. In both cases, the algorithm consistently converges towards high-quality sweet spots. Since tunnelling spectroscopy provides one global metric for tuning all on-site potentials simultaneously, this presents a promising way towards tuning longer Kitaev chains, which are required for achieving topological protection of the Majorana modes.

[6]  arXiv:2405.01334 [pdf, ps, other]

Title: Nutation: separating the spin from its magnetic moment

Authors: Anulekha De, Julius Schlegel, Akira Lentfert, Laura Scheuer, Benjamin Stadtmüller, Philipp Pirro, Georg von Freymann, Ulrich Nowak, Martin Aeschlimann

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

For nearly 90 years, precession and relaxation processes have been thought to dominate magnetization dynamics. Only recently has it been considered that, on short time scales, an inertia-driven magnetization dynamics should become relevant, leading to additional nutation of the magnetization vector. Here, we trigger magnetic nutation via a sudden excitation of a thin Ni80Fe20 (Permalloy) film with an ultrashort optical pulse, that leads to an abrupt tilting of the effective field acting on the magnetic moments, separating the dynamics of the magnetization from that of its angular momentum. We investigate the resulting magnetization dynamics in the inertial regime experimentally by the time-resolved magneto optical Kerr effect. We find a characteristic oscillation in the Kerr signal in the range of about 0.1 THz superimposed on the precessional oscillations with GHz frequencies. By comparison with atomistic spin dynamics simulations, we demonstrate that this observation cannot be explained by the well-known Landau-Lifshitz-Gilbert equation of motion but can be attributed to inertial contributions leading to nutation of the magnetization vector around its angular momentum. Hence, an optical and non-resonant excitation of inertial magnetization dynamics can trigger and control different magnetic processes, ranging from demagnetization via nutation to precession in a single device. These findings will have profound implications for the understanding of ultrafast spin dynamics and magnetization switching.

[7]  arXiv:2405.01351 [pdf, other]

Title: High harmonic generation from electrons moving on topological spin textures

Authors: Atsushi Ono, Shun Okumura, Shohei Imai, Yutaka Akagi

Comments: 15 pages, 15 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Strongly Correlated Electrons (cond-mat.str-el)

High harmonic generation (HHG) is a striking phenomenon, which reflects the ultrafast dynamics of electrons. Recently, it has been demonstrated that HHG can be used to reconstruct not only the energy band structure but also the geometric structure characterized by the Berry curvature. Here, we numerically investigate HHG arising from electrons coupled with a topological spin texture in a spin scalar chiral state where time reversal symmetry is broken. In this system, a sign change in scalar chirality alters the sign of the Berry curvature while keeping the energy band structure unchanged, allowing us to discuss purely geometrical effects on HHG. Notably, we found that, when the optical frequency is significantly lower than the energy gap, the sign of scalar chirality largely affects the longitudinal response parallel to the optical field rather than the transverse response. Our analysis suggests that this can be attributed to interband currents induced by the recombination of electron-hole pairs whose real-space trajectories are modulated by the anomalous velocity term.

Cross-lists for Fri, 3 May 24

[8]  arXiv:2405.00783 (cross-list from cond-mat.stat-mech) [pdf, other]

Title: Microscopic origin of twist-dependent electron transfer rate in bilayer graphene

Authors: Leonardo Coello Escalante, David T. Limmer

Subjects: Statistical Mechanics (cond-mat.stat-mech); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Chemical Physics (physics.chem-ph)

Using molecular simulation and continuum dielectric theory, we consider how electrochemical kinetics are modulated as a function of twist angle in bilayer graphene electrodes. By establishing an effective connection between twist angle and the screening length of charge carriers within the electrode, we investigate how tunable metallicity can result in modified statistics of the electron transfer energy gap. Constant potential molecular simulations show that the activation free energy for electron transfer is an increasing function of the screening length, or decreasing function the density of states at the Fermi energy in the electrode, and subsequently a non-monotonic function of twist angle. We find the twist angle alters the density of states, which tunes the number of thermally-accessible channels for electron transfer, as well as the reorganization energy by altering the stability of the vertically excited state through attenuated image charge interactions. Understanding these effects allows us to cast the Marcus rate of interfacial electron transfer as a function of twist angle, in a manner consistent with a growing body of experimental observations.

[9]  arXiv:2405.00873 (cross-list from quant-ph) [pdf, other]

Title: Implementing a synthetic magnetic vector potential in a 2D superconducting qubit array

Authors: Ilan T. Rosen, Sarah Muschinske, Cora N. Barrett, Arkya Chatterjee, Max Hays, Michael DeMarco, Amir Karamlou, David Rower, Rabindra Das, David K. Kim, Bethany M. Niedzielski, Meghan Schuldt, Kyle Serniak, Mollie E. Schwartz, Jonilyn L. Yoder, Jeffrey A. Grover, William D. Oliver

Comments: 9 pages, 5 figures, and Supplementary Information

Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Superconducting quantum processors are a compelling platform for analog quantum simulation due to the precision control, fast operation, and site-resolved readout inherent to the hardware. Arrays of coupled superconducting qubits natively emulate the dynamics of interacting particles according to the Bose-Hubbard model. However, many interesting condensed-matter phenomena emerge only in the presence of electromagnetic fields. Here, we emulate the dynamics of charged particles in an electromagnetic field using a superconducting quantum simulator. We realize a broadly adjustable synthetic magnetic vector potential by applying continuous modulation tones to all qubits. We verify that the synthetic vector potential obeys requisite properties of electromagnetism: a spatially-varying vector potential breaks time-reversal symmetry and generates a gauge-invariant synthetic magnetic field, and a temporally-varying vector potential produces a synthetic electric field. We demonstrate that the Hall effect--the transverse deflection of a charged particle propagating in an electromagnetic field--exists in the presence of the synthetic electromagnetic field.

[10]  arXiv:2405.01059 (cross-list from quant-ph) [pdf, ps, other]

Title: Dense dipole-dipole-coupled two-level systems in a thermal bath

Authors: Mihai A. Macovei

Comments: 6 pages, 4 figures

Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Atomic and Molecular Clusters (physics.atm-clus)

The quantum dynamics of a dense and dipole-dipole coupled ensemble of two-level emitters interacting via their environmental thermostat is investigated. The static dipole-dipole interaction strengths are being considered strong enough but smaller than the transition frequency. Therefore, the established thermal equilibrium of ensemble's quantum dynamics is described with respect to the dipole-dipole coupling strengths. We have demonstrated the quantum nature of the spontaneously scattered light field in this process for weaker thermal baths as well as non-negligible dipole-dipole couplings compared to the emitter's transition frequency. Furthermore, the collectively emitted photon intensity suppresses or enhances depending on the environmental thermal baths intensities.

[11]  arXiv:2405.01331 (cross-list from cond-mat.mtrl-sci) [pdf, other]

Title: On Nanowire Morphological Instability and Pinch-Off by Surface Electromigration

Authors: Mikhail Khenner

Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Mathematical Physics (math-ph); Applied Physics (physics.app-ph)

Surface diffusion and surface electromigration may lead to a morphological instability of thin solid films and nanowires. In this paper two nonlinear analyzes of a morphological instability are developed for a single-crystal cylindrical nanowire that is subjected to the axial current. These treatments extend the conventional linear stability analyzes without surface electromigration, that manifest a Rayleigh-Plateau instability. A weakly nonlinear analysis is done slightly above the Rayleigh-Plateau (longwave) instability threshold. It results in a one-dimensional Sivashinsky amplitude equation that describes a blow-up of a surface perturbation amplitude in a finite time. This is a signature of a formation of an axisymmetric spike singularity of a cylinder radius, which leads to a wire pinch-off and separation into a disjoint segments. The scaling analysis of the amplitude spike singularity is performed, and the time-and-electric field-dependent dimensions of the spike are characterized. A weakly nonlinear multi-scale analysis is done at the arbitrary distance above a longwave or a shortwave instability threshold. The time-and-electric field-dependent Fourier amplitudes of the major instability modes are derived and characterized.

[12]  arXiv:2405.01377 (cross-list from physics.class-ph) [pdf, other]

Title: Nonlinearity-induced symmetry breaking in a system of two parametrically driven Kerr-Duffing oscillators

Authors: F. Hellbach, D. De Bernardis, M. Saur, I. Carusotto, W. Belzig, G. Rastelli

Subjects: Classical Physics (physics.class-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Optics (physics.optics)

We study the classical dynamics of a system of a pair of Kerr-Duffing nonlinear oscillators coupled by a nonlinear interaction and subject to a parametric drive. Within a rotating wave approximation (RWA), we analyze the steady-state solutions for the oscillation amplitude of the two oscillators. In the most relevant case of identical oscillators, we separately investigate configurations in which only one oscillator is parametrically driven, or both of them are simultaneously driven. In the latter regime, special attention is paid to the symmetric case where the parametric drives acting on the two oscillators are equal: for an increasing value of the detuning of the parametric drive, a transition to a multi-stable, symmetry-breaking regime is found, where the two oscillators display different oscillation amplitudes and phases.

Replacements for Fri, 3 May 24

[13]  arXiv:2302.09099 (replaced) [pdf, other]

Title: Universality and the thermoelectric transport properties of a double quantum dot system: Seeking for conditions that improve the thermoelectric efficiency

Authors: R. S. Cortes-Santamaria (1), J. A. Landazabal-Rodríguez (2), J.Silva-Valencia (1), E. Ramos (3), M. S. Figueira (4), R. Franco (1)

Comments: 13 pages, 12 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); Strongly Correlated Electrons (cond-mat.str-el)

[14]  arXiv:2304.13442 (replaced) [pdf, other]

Title: Multi-module microwave assembly for fast read-out and charge noise characterization of silicon quantum dots

Authors: Felix-Ekkehard von Horstig, David J. Ibberson, Giovanni A. Oakes, Laurence Cochrane, David F. Wise, Nadia Stelmashenko, Sylvain Barraud, Jason A. W. Robinson, Frederico Martins, M. Fernando Gonzalez-Zalba

Comments: Main: 8 pages, 4 figures. Supplementary: 4 pages, 7 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

[15]  arXiv:2307.04789 (replaced) [pdf, other]

Title: Anomalous Andreev Spectrum and Transport in Non-Hermitian Josephson Junctions

Authors: Chang-An Li, Hai-Peng Sun, Björn Trauzettel

Comments: 9 pages, 4 figures

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

[16]  arXiv:2308.16908 (replaced) [pdf, other]

Title: Quantized thermal and spin transports of dirty planar topological superconductors

Authors: Sanjib Kumar Das, Bitan Roy

Comments: Published version in PRB: 13 pages, 4 figures, 1 Table

Journal-ref: Phys. Rev. B 109, 195403 (2024)

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Disordered Systems and Neural Networks (cond-mat.dis-nn); Strongly Correlated Electrons (cond-mat.str-el); Superconductivity (cond-mat.supr-con)

[17]  arXiv:2403.00052 (replaced) [pdf, other]

Title: Long-lived Topological Flatband Excitons in Semiconductor Moiré Heterostructures: a Bosonic Kane-Mele Model Platform

Authors: Ming Xie, Mohammad Hafezi, Sankar Das Sarma

Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

[18]  arXiv:2307.04854 (replaced) [pdf, other]

Title: Unconventional quantum oscillations and evidence of non-trivial electronic states in quasi-two-dimensional electron system at complex oxide interfaces

Authors: Km Rubi, Denis R. Candido, Manish Dumen, Shengwei Zeng, Andrew Ammerlaan, Femke Bangma, Mun K. Chan, Michel Goiran, Ariando Ariando, Suvankar Chakraverty, Walter Escoffier, Uli Zeitler, Neil Harrison

Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

[19]  arXiv:2309.06765 (replaced) [pdf, other]

Title: Single-photon induced instabilities in a cavity electromechanical device

Authors: Tanmoy Bera, Mridul Kandpal, G. S. Agarwal, Vibhor Singh

Comments: Total 25 pages with 12 figures (6 Main, 6 Supplementary)

Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

[20]  arXiv:2310.02184 (replaced) [pdf, other]

Title: Electronic structure in a rare-earth based nodal-line semimetal candidate PrSbTe

Authors: Sabin Regmi, Iftakhar Bin Elius, Anup Pradhan Sakhya, Milo Sprague, Mazharul Islam Mondal, Nathan Valadez, Volodymyr Buturlim, Kali Booth, Tetiana Romanova, Krzysztof Gofryk, Andrzej Ptok, Dariusz Kaczorowski, Madhab Neupane

Comments: 26 pages, 11 figures; SUPPLEMENTAL MATERIAL included

Journal-ref: Phys. Rev. Materials 8, L041201 (2024)

Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

[21]  arXiv:2310.07978 (replaced) [pdf, other]

Title: Anderson localization transition in disordered hyperbolic lattices

Authors: Anffany Chen, Joseph Maciejko, Igor Boettcher

Comments: main text (5 pages with 3 figures) + bibliography (2 pages) + supplemental material (8 pages with 6 figures and 3 tables)

Subjects: Disordered Systems and Neural Networks (cond-mat.dis-nn); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Statistical Mechanics (cond-mat.stat-mech); Strongly Correlated Electrons (cond-mat.str-el); Mathematical Physics (math-ph)

[22]  arXiv:2401.03028 (replaced) [pdf, other]

Title: Phase transitions and scale invariance in topological Anderson insulators

Authors: Bryan D. Assunção, Gerson J. Ferreira, Caio H. Lewenkopf

Comments: 7 pages, 4 figures, and a supplemental material with 7 pages, 4 figures

Journal-ref: Phys. Rev. B 109, L201102 (2024)

Subjects: Disordered Systems and Neural Networks (cond-mat.dis-nn); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

[23]  arXiv:2404.10814 (replaced) [pdf, other]

Title: Higher Hall conductivity from a single wave function: Obstructions to symmetry-preserving gapped edge of (2+1)D topological order

Authors: Ryohei Kobayashi, Taige Wang, Tomohiro Soejima, Roger S. K. Mong, Shinsei Ryu

Comments: 17 pages, 4 figures, minor edits

Subjects: Strongly Correlated Electrons (cond-mat.str-el); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)

[24]  arXiv:2404.19153 (replaced) [pdf, other]

Title: Room temperature realization of artificial chiral magnets with reprogrammable magnon nonreciprocity at zero field

Authors: Mingran Xu, Axel J. M. Deenen, Huixin Guo, Dirk Grundler

Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Applied Physics (physics.app-ph)

• New submissions
• Cross-lists
• Replacements