Article
Physics, Applied
Qian Xie, Shuai Yuan, Ye Ji, Shilong Feng, Yulan Liu, Biao Wang
Summary: Polar topologies with exotic textures and functionalities in low-dimensional ferroelectrics have been receiving extensive attention. This study proposes a scheme to generate local torsional force through electric field excitation, namely the electric torsion effect in a ferroelectric nanodot, using phase-field simulation. The results demonstrate that the twisting response resulting from structural phase transitions between vortex and helical states can be controlled by manipulating the external electric fields in terms of magnitude and orientation. This work provides further understanding of the electromechanical response of polar topologies and may facilitate the development of torsion-based device applications in ferroelectric nanoelectronics.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Kalani Moore, Ursel Bangert, Michele Conroy
Summary: Advancements in electron microscopy have allowed for the exploration of the complex nature of ferroelectric topological defects, observing changes in polarization, chemical composition, charge density, and strain. Current achievements include mapping the 3D nature of ferroelectric polar skyrmions and in situ biasing. The research focuses on understanding the fundamental physics and dynamics of domain wall and polar vortex formation in ferroelectrics.
Article
Physics, Multidisciplinary
Oswaldo Dieguez, Massimiliano Stengel
Summary: Macroscopic descriptions of ferroelectrics have limitations in terms of predicting materials parameters from microscopic structures. This study establishes a two-way mapping between spatially inhomogeneous fields and discrete lattice modes, enabling a natural treatment of gradient couplings in the macroscopic regime. The findings reveal a generalized translational covariance in the continuum description of inhomogeneous ferroelectric structures, canceling out the inherent arbitrariness in flexoelectric and polarization gradient coefficients.
Article
Chemistry, Multidisciplinary
Erik D. Roede, Konstantin Shapovalov, Thomas J. Moran, Aleksander B. Mosberg, Zewu Yan, Edith Bourret, Andres Cano, Bryan D. Huey, Antonius T. J. van Helvoort, Dennis Meier
Summary: This study demonstrates the importance of nanoscale structure for the emergent transport properties in the 3D network of neutral and charged domain walls in ErMnO3. By using tomographic microscopy techniques and finite element modeling, the contribution of domain walls within the bulk is clarified and the significance of curvature effects for the local conduction is shown down to the nanoscale.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Pavel Marton, Mauro A. P. Goncalves, Marek Pasciak, Sabine Koerbel, Venceslav Chumchal, Martin Plesinger, Antonin Klic, Jirka Hlinka
Summary: We conducted a theoretical investigation on a charged 180 degrees domain wall in ferroelectric PbTiO3, compensated by randomly distributed immobile charge defects, using atomistic shell-model simulations and continuous phase-field simulations. Our predictions show that the domain walls form a zigzag pattern, accompanied by local polarization rotation, which provides an efficient mechanism for charge compensation.
Article
Chemistry, Multidisciplinary
Edmund Han, Shahriar Muhammad Nahid, Tawfiqur Rakib, Gillian Nolan, Paolo F. Ferrari, M. Abir Hossain, Andre Schleife, SungWoo Nam, Elif Ertekin, Arend M. van der Zande, Pinshane Y. Huang
Summary: The low bending stiffness of atomic membranes from van der Waals ferroelectrics such as alpha-In2Se3 allows strong coupling between electrical polarization and mechanical deformation at high strain gradients and nanoscale curvatures. By investigating the atomic structure and polarization at bends in multilayer alpha-In2Se3, researchers found that bent alpha-In2Se3 produces arcs and kinks, with the former preserving the original polarization and the latter containing ferroelectric domain walls that reverse the out-of-plane polarization. The study demonstrates the control over ferroelectric polarization and a strategy for nanoscale ferroelectric domain patterning.
Article
Materials Science, Multidisciplinary
Duk-Hyun Choe, Sunghyun Kim, Taehwan Moon, Sanghyun Jo, Hagyoul Bae, Seung-Geol Nam, Yun Seong Lee, Jinseong Heo
Summary: A new topological class of domain walls in orthorhombic HfO2 was discovered, revealing an atomic-scale mechanism of polarization switching with unexpectedly low energy barriers of domain wall motion. This challenges previous beliefs and provides a strategy to reduce coercive fields in HfO2-based ferroelectric devices.
Article
Physics, Applied
X. M. Cui, W. J. Zhai, Y. Zhang, L. Huang, Y. S. Tang, C. F. Li, Y. Q. Li, L. Lin, Z. B. Yan, X. P. Jiang, J-M Liu
Summary: This study discusses various approaches to constructing modified thermodynamic potentials under epitaxial thin film boundary conditions, establishing the equivalence of these potentials and utilizing K0.5Na0.5NbO3 thin films as an example for practical calculations. It also examines a set of misfit strain-strain phase diagrams and discusses scenarios for choosing different thermodynamic potentials for ferroelectric thin films.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Salvatore Perna, Patrizio Ansalone, Massimiliano d'Aquino, Valentino Scalera, Claudio Serpico, Vittorio Basso
Summary: The role of the electric field on the magnetic ground state in thin disks is investigated, and the equation governing the magnetic equilibrium is derived and solved by varying electric and magnetic fields. The equilibrium states obtained are classified in a phase diagram, which divides the plane of the electric and magnetic fields based on the shape of magnetization profile. Full micromagnetic simulations are used for confirmation.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Chemistry, Multidisciplinary
Jan Schultheiss, Erik Lysne, Lukas Puntigam, Jakob Schaab, Edith Bourret, Zewu Yan, Stephan Krohns, Dennis Meier
Summary: The charge state of domain walls affects their behavior in both direct and alternating electrical fields. While charged walls show unique responses to alternating currents compared to the surrounding domains, voltage-dependent spectroscopic measurements reveal pronounced nonlinear responses at the electrode-wall junction, enabling reversible switching between unipolar and bipolar output signals.
Article
Physics, Applied
Lukas Puntigam, Jan Schultheiss, Ana Strinic, Zewu Yan, Edith Bourret, Markus Altthaler, Istvan Kezsmarki, Donald M. Evans, Dennis Meier, Stephan Krohns
Summary: This study reports the dielectric properties of improper ferroelectric material h-ErMnO3, revealing two distinct relaxation features contributing to high and even colossal dielectric permittivity values. The internal barrier layer capacitance (BLC) related to insulating domain walls is found to play a significant role in the high dielectric constants observed in the material. Unlike proper ferroelectrics, in h-ErMnO3, the insulating domain walls are topologically protected, enabling operation under substantially higher electric fields.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Dongfeng Zheng, Guo Tian, Yadong Wang, Wenda Yang, Luyong Zhang, Zoufei Chen, Zhen Fan, Deyang Chen, Zhipeng Hou, Xingsen Gao, Qiliang Li, Jun-Ming Liu
Summary: In this study, the controlled manipulation of conductive domain walls in epitaxial BiFeO3 thin films was demonstrated using piezoresponse force microscopy and conductive atomic force microscopy. It was also found that nanoscale domains surrounded by highly conductive circular charged domain walls can be created and erased through the application of local field using a conductive probe.
JOURNAL OF MATERIOMICS
(2022)
Article
Nanoscience & Nanotechnology
P. C. Xiong, W. B. Ma, S. Yuan, Y. L. Liu, B. Wang
Summary: Phase-field calculations were used to simulate the manipulation of a ferroelectric vortex under the boundary condition of inhomogeneous screening. It was found that the vortex chirality can be tuned by utilizing uniform electric fields under inhomogeneous screening boundary conditions, and the switching mechanism is distinct from that under boundary conditions of asymmetric screening previously reported. The influence of the screening inhomogeneity and the ambient temperature on the vortex switching was further studied, indicating their vital importance in the switching behaviors of vortex chirality.
Article
Physics, Multidisciplinary
Youngjun Ahn, Arnoud S. Everhardt, Hyeon Jun Lee, Joonkyu Park, Anastasios Pateras, Silvia Damerio, Tao Zhou, Anthony D. DiChiara, Haidan Wen, Beatriz Noheda, Paul G. Evans
Summary: Optical excitation disrupts the balance of phenomena selecting the tilt orientation of domain walls within ferroelectric thin films. Tilting of domain walls occurs at 298 K due to the coexistence of a/b and a/c domain phases, leading to increased domain-wall charge density. This screening mechanism points to new directions for the manipulation of nanoscale ferroelectricity.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Maria Jose Cortes Burgos, Pamela C. Guruciaga, Daniel Jordan, Cynthia P. Quinteros, Elisabeth Agoritsas, Javier Curiale, Mara Granada, Sebastian Bustingorry
Summary: The study investigates the creep motion of domain walls in magnetic thin films driven by external fields and discusses the roughness exponent and amplitude, with experimental results showing an average roughness exponent value of 0.74 and a significant increase in roughness amplitude with decreasing field intensity. These results contribute to understanding domain wall motion in disordered magnetic thin systems.
Article
Physics, Multidisciplinary
A. -M Visuri, T. Giamarchi, C. Kollath
Summary: This paper studies particle transport through a chain of coupled sites connected to free-fermion reservoirs at both ends, with a local particle loss. The conductance and particle density in the steady state are calculated using the Keldysh formalism for open quantum systems. In addition to a reduction in conductance, it is found that transport can remain (almost) unaffected by the loss for certain values of the chemical potential in the lattice. It is shown that this protected transport is a result of the spatial symmetry of single-particle eigenstates. At a finite voltage, the density profile develops a drop at the lossy site, connected to the onset of nonballistic transport.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Shintaro Takayoshi, Thierry Giamarchi
Summary: We study the transport properties of a one-dimensional quantum system with disorder and compute the frequency dependence of its conductivity using numerical methods. The results show that the conductivity decays as a power law at high frequencies and follows a linear behavior at low frequencies, with both behaviors being affected by the interaction strength. The localization length also exhibits a power law dependence on the disorder strength, in agreement with theoretical predictions. These findings have implications for experiments with cold atomic gases.
EUROPEAN PHYSICAL JOURNAL D
(2022)
Article
Physics, Multidisciplinary
Paola Ruggiero, Pasquale Calabrese, Thierry Giamarchi, Laura Foini
Summary: This article studies the correlation functions after a quantum quench of a gaussian field problem, providing a fully analytical solution using the electrostatic analogy and charge images method. This analytical solution allows for obtaining all correlation functions in imaginary time, recovering and generalizing the results in real time.
Article
Physics, Multidisciplinary
Meng-Zi Huang, Jeffrey Mohan, Anne -Maria Visuri, Philipp Fabritius, Mohsen Talebi, Simon Wili, Shun Uchino, Thierry Giamarchi, Tilman Esslinger
Summary: We measure the superfluid transport of strongly interacting fermionic lithium atoms through a quantum point contact by utilizing local, spin-dependent particle loss. We find that the characteristic non-Ohmic superfluid transport, enabled by high-order multiple Andreev reflections, transitions into an excess Ohmic current when the dissipation strength exceeds the superfluid gap. Our developed model, which includes mean-field reservoirs connected to a dissipative site via tunneling, reproduces the observed nonequilibrium particle current in the Keldysh formalism, but it does not fully explain the observed loss rate or spin current.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Hugo Cayla, Pietro Massignan, Thierry Giamarchi, Alain Aspect, Christoph I. Westbrook, David Clement
Summary: We measured the momentum density in a Bose-Einstein condensate (BEC) with dilute spin impurities and observed algebraic tails decaying as 1/k4 at large momentum k, which originated from impurity-BEC interactions. The amplitudes of these tails exceeded those expected from two-body contact interactions at equilibrium in the trap. These unexpected algebraic tails were found to originate from the nontrivial dynamics of the expansion in the presence of impurity-bath interactions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Gunnar Bollmark, Thomas Kohler, Lorenzo Pizzino, Yiqi Yang, Johannes S. Hofmann, Hao Shi, Shiwei Zhang, Thierry Giamarchi, Adrian Kantian
Summary: Correlated electron states are crucial for understanding unconventional superconductivity. However, calculating their properties accurately remains a challenge. In this work, we propose a framework combining matrix product states (MPS) with mean field (MF) to compute the properties of quasi-one-dimensional (Q1D) systems. We demonstrate the effectiveness of this framework by calculating the critical temperature for superconductivity in Q1D fermions. This approach allows for the quantitative study of correlated phases and the treatment of competing macroscopic orders.
Article
Mechanics
Federico Lanza, Santanu Sinha, Alex Hansen, Alberto Rosso, Laurent Talon
Summary: In this study, we investigate the behavior of drainage displacements in heterogeneous porous media and find a transition from viscous fingering to foam-like region. By using a pore network model, we analyze the transition distance and its dependence on viscosity ratio and capillary number. Additionally, we discuss the relationship between the evolution of total flow rate and local pressure drop, and observe that foam formation is related to the fragmentation of viscous fingers.
Article
Multidisciplinary Sciences
T. -W. Zhou, G. Cappellini, D. Tusi, L. Franchi, J. Parravicini, C. Repellin, S. Greschner, M. Inguscio, T. Giamarchi, M. Filippone, J. Catani, L. Fallani
Summary: The Hall effect, which describes the motion of charged particles in magnetic fields, has important implications for material properties. Understanding this effect in interacting systems is challenging, even for small magnetic fields. In this study, we used an atomic quantum simulator to investigate the behavior of ultracold fermions in the presence of artificial magnetic fields. Through experimental measurements, we observed a universal behavior of the Hall response, which is independent of the strength of atomic interactions. This research demonstrates the capability of quantum simulation to describe strongly correlated topological states of matter.
Article
Materials Science, Multidisciplinary
Tony Jin, Paola Ruggiero, Thierry Giamarchi
Summary: We derive the bosonization of the interacting fermionic Su-Schrieffer-Heeger (SSH) model with open boundaries and use it to quantitatively describe the edge modes of the system. Our results show excellent agreement with numerical simulations, particularly in terms of the localization of the zero-energy edge mode near the boundaries. Interestingly, we find that the effects of repulsive or attractive interactions on the edge mode localization depend on the staggering parameter. We provide quantitative predictions of these effects on the localization length of the edge mode and suggest that bosonization can be generalized to other models.
Article
Materials Science, Multidisciplinary
Saptarshi Majumdar, Laura Foini, Thierry Giamarchi, Alberto Rosso
Summary: We study an XXZ spin chain coupled to an ohmic bath of harmonic oscillators at zero temperature. Two phases, separated by a Kosterlitz-Thouless transition, are found: a Luttinger liquid phase with finite spin stiffness at low coupling and a dissipative phase with vanishing spin stiffness at high coupling. The transport properties are also affected, with the Luttinger liquid phase being a perfect conductor and the dissipative phase showing finite resistivity. The effect of the bath can be interpreted as annealed disorder-inducing signatures of localization.
Article
Physics, Multidisciplinary
A. -M. Visuri, T. Giamarchi, C. Kollath
Summary: This paper investigates particle transport, particle loss, and nonequilibrium steady states in a dissipative one-dimensional lattice connected to reservoirs at both ends. By applying local particle loss to the center site, particle transport is generated between free-fermion reservoirs with different chemical potentials. The conserved current and loss current as functions of voltage in the nonlinear regime are computed using a Keldysh description. The behaviors of the currents are affected differently by the local loss, resulting in either smoothed, nearly unaffected, or even enhanced steps depending on the spatial symmetry of the single-particle eigenstate.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Multidisciplinary
Tony Jin, Joao Ferreira, Michel Bauer, Michele Filippone, Thierry Giamarchi
Summary: We have developed a semiclassical model to study the transport properties of low-dimensional fermionic lattices under the influence of external quantum stochastic noise. These systems exhibit behavior similar to quantum stochastic resistors, where bulk particle transport is diffusive and follows Ohm's/Fick's law. By extending previous studies beyond one-dimensional systems to ladder geometries, we have explored different dephasing mechanisms relevant to various physical systems. Our results show that the semiclassical description provides a useful and simpler interpretation of the conductance dependence on chemical potential, which agrees well with exact numerical solutions. Additionally, we have found that the coherence of the dephasing process in the transverse direction does not affect the conductance of quantum ladders, despite different stationary states being reached.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Multidisciplinary
Catalin-Mihai Halati, Thierry Giamarchi
Summary: We investigate the properties of interacting bosonic particles on a two-leg triangular ladder with an artificial gauge field. By using numerical simulations and analytical bosonization calculations, we explore the complex phase diagram of this system. The interplay between the frustration from the triangular lattice geometry and the interactions leads to the emergence of multiple chiral quantum phases. Phase transitions from superfluid to Mott-insulating states occur, exhibiting Meissner or vortex characteristics. Moreover, we discover a biased chiral superfluid state that breaks the symmetry between the two legs of the ladder, particularly for flux values close to pi. In the regime of hard-core bosons, we demonstrate the extension of the bond order insulator, beyond the fully frustrated ladder case, with Meissner-type chiral currents. We discuss the implications of our findings for experimental studies in cold atomic systems.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Federico Elias, Alejandro B. Kolton
Summary: We study the deterministic dispersion of particles uniformly driven in an array of narrow tracks induced by disorder. We obtain analytical expressions for the mean velocity and dispersion constant for different toy models with quenched disorder. We find that the relationship between the dispersion constant and velocity depends on the type of disorder. These results are robust across different models and effects, and may have implications for understanding the dynamics of stable localized objects in various systems.
Article
Materials Science, Multidisciplinary
Federico Elias, Alejandro B. Kolton, Kay Jorg Wiese
Summary: In this study, the dynamics of a single directed elastic string driven through a three-dimensional disordered medium is investigated numerically and analytically. The results show that in the driving direction, the string is super-rough with certain roughness, dynamic, correlation-length, depinning, and avalanche-size exponents. The transverse fluctuations do not affect the critical exponents in the driving direction. Random-bond and random-field disorder yield the same universality class as a two-dimensional random medium. The distribution of local displacements has different characteristics in the parallel and transverse directions.
