A metal can be driven to an insulating phase through distinct mechanisms. A possible way is via the Coulomb interaction, which then defines the Mott metal-insulator transition (MIT). Another possibility is the MIT driven by disorder, the so-called Anderson MIT. Here we analyze interacting particles in disordered Hubbard chains---thus comprising the Mott-Anderson physics---by investigating the ground-state entanglement with density functional theory. The localization signature on entanglement is found to be a decreasing on the entanglement degree in comparison to the clean (without interaction and disorder) case, with local minima at certain critical densities. Individually, the Mott (Anderson) MIT has a single critical density whose minimum entanglement decreases as the interaction (disorder) enhances. While in the Mott MIT entanglement saturates at finite values, characterizing partial localization, in the Anderson MIT the system reaches full localization, with zero entanglement, for sufficiently strong disorder. In the combined Mott-Anderson MIT, we find three critical densities referring to local minima on entanglement. One of them is the same as for the Anderson MIT, but now the presence of interaction requires a stronger disorder potential to induce full localization. A second critical density is related to the Mott MIT, but due to disorder it is displaced by a factor proportional to the concentration of impurities. The third local minimum on entanglement is unique to the concomitant presence of disorder and interaction, found to be related to an effective density phenomenon, thus referred to as a Mott-like MIT. Since entanglement has been intrinsically connected to the magnetic susceptibility---a quantity promptly available in cold-atom experiments---our detailed numerical description might be useful for the experimental investigation of the Mott-Anderson MIT.

Mott-Anderson metal-insulator transitions from entanglement

Here, we report the growth of (Sr, Ca) Nd2Fe2O7 single crystals with the Ruddlesden–Popper structure using an optical floating-zone method. A significantly anisotropic magneto-dielectric effect (MD), ab-plane and c-axial MD coefficients reaching −12.3% and −8.4% measured at 103 Hz in a 1 T magnetic field, can be obtained in a SrNd2Fe2O7 crystal at room temperature. The corresponding anisotropic MD ratio can be reached as high as 1.46. With an increase in the Ca concentration, the MD effect decreases dramatically and is eventually completely suppressed in both directions. Analysis of magnetic properties and 57Fe Mössbauer spectra suggests that the anisotropic MD effects in SrNd2Fe2O7 can be attributed to polaronic hopping between two neighboring Fe3+ ions through oxygen vacancies in an anisotropically antiferromagnetic matrix; the disappearance of the MD effect in Ca-doped SrNd2Fe2O7 is a consequence of the suppression of the antiferromagnetism. Our work suggests that the significantly anisotropic MD effect in SrNd2Fe2O7 crystals at room temperature can be used in magneto-dielectric controlled devices.

Significant magneto-dielectric effect in SrNd2Fe2O7 at room temperature

Production of electron-positron pairs in two oscillating strong electric field pulses with largely different frequencies and durations is considered. In a first scenario, the influence of a low-frequency background field on pair production by a short main pulse of high frequency is analyzed. The background field is shown to cause characteristic modifications of the momentum spectra of created particles, which, in turn, may be used for imaging of the background pulse. In a second scenario, an ultrashort, relatively weak assisting pulse is superimposed onto a strong main pulse. By studying the dependence of the pair production on the field parameters it is shown that duration and relative position of the ultrashort pulse modify the momentum spectra of produced particles in a distinctive way. Both scenarios enable one, moreover, to extract partial information about the time periods when pairs with certain momenta are produced predominantly. 

Electron-positron-pair creation in the superposition of two oscillating electric-field pulses with largely different frequency, duration, and relative positioning

We examine the electron-positron pair-creation process from the quantum vacuum triggered by two colliding laser beams in the presence of a nuclear binding potential. Once the two pulses overlap, they form a standing-wave pattern with nodes or antinodes in the region where the nucleus is placed. As the resulting spatial intensity pattern depends on the phase between both fields, it can be used to control the pair-creation yield. It turns out that the ground-state capture of the created electrons can actually be largest for those laser phases that lead to nodes (dark intensity regions) where the nucleus is located and not for those that lead to antinodes (bright intensity regions). Furthermore, this phase can be used to control selectively into which excited state the created electrons are predominately captured. 

Phase sensitivity of the pair-creation process in colliding laser pulses

Spins in strongly frustrated systems are of intense interest due to the emergence of intriguing quantum states including superconductivity and quantum spin liquid. Herein we report the discovery of cascade of phase transitions and large magnetic anisotropy in the averievite CsClCu5P2O10 single crystals. Under zero field, CsClCu5P2O10 undergoes a first-order structural transition at around 225 K from high temperature centrosymmetric P-3m1 to low temperature noncentrosymmetric P321, followed by an AFM transition at 13.6 K, another structural transition centering at ~3 K, and another AFM transition at ~2.18 K. Based upon magnetic susceptibility and magnetization data with magnetic fields perpendicular to the ab plane, a phase diagram, consisting of a paramagnetic state, two AFM states and four field-induced states including two magnetization plateaus, has been constructed. Our findings demonstrate that the quasi-2D CsClCu5P2O10 exhibits rich structural and metamagnetic transitions and the averievite family is a fertile platform for exploring novel quantum states.

Cascade of Phase Transitions and Large Magnetic Anisotropy in a Triangle-Kagome-Triangle Trilayer Antiferromagnet

We study the critical behavior of the single-site entanglement entropy S at the Mott metal-insulator transition in infinite-dimensional Hubbard model. For this model, the entanglement between a single site and rest of the lattice can be evaluated exactly, using the dynamical mean-field theory (DMFT). Both the numerical solution using exact diagonalization and the analytical one using two-site DMFT gives S - Sc ∝ α log2[(1/2 - Dc)/Dc](U - Uc), with Dc the double occupancy at Uc and α < 0 being different on two sides of the transition.

Local entanglement entropy at the mott metal-insulator transition in infinite dimensions

A highly charged nucleus can induce spatial structures into the otherwise spatially homogeneous Dirac quantum vacuum state. We propose that the electron-positron pair creation process triggered by two counter-propagating laser pulses can be used to probe these structures. The particle yield can be controlled by the phase relationship between the beams. Once the pulses overlap, they form standing waves whose nodal patterns are determined by this laser phase. Due to the spatial deformation of the vacuum state, the maximal pair creation yield is observed for those phases that lead to nodes (and not anti-nodes!) where the nucleus is located. This means rather counterintuitively that the particle yield is maximum, despite the fact that the electrical field intensity almost vanishes in the interaction zone.

Probing the spatial structure of the Dirac vacuum via phase-controlled colliding laser pulses

High-field magnetization and magnetodielectric effect in a 
Ni2NbBO6
 single crystal

The Dzyaloshinskii-Moriya interaction (DMI) is a key factor in chiral spin textures and has great potential in spintronics-based applications. The asymmetric bubble domain expansion under an in-plane magnetic field is a common method for DMI evaluation. However, abnormal bubble expansions occur occasionally in the creep regime, which may lead to deviations in the DMI evaluation, implying various physical phenomena in domain wall (DW) kinetics. In this study, DMI evaluation of ferrimagnetic Pt/Co/Tb trilayers was conducted via DW motion in the creep and flow regimes, where the in-plane fields of minimum DW velocities are significantly different for 1.5 nm Co. The accuracy of the extracted DMI effective field in the flow regime was confirmed by Brillouin light scattering measurements, where the DMI coefficient was approximately $1\phantom{\rule{0.28em}{0ex}}\mathrm{mJ}/{\mathrm{m}}^{2}$. In the creep regime, a typical flattened bubble shape was observed; accordingly, the dominant direction of the DW motion velocity changes with increasing the in-plane magnetic fields. Based on the bubble morphology and DW anisotropy energy analyses, we attributed the bubble expansion phenomena in the creep regime to the vertical Bloch lines. Our study provides alternatives for a better understanding of DW kinetics in DMI evaluations, which is essential for spin-texture applications. 

Chiral morphology in ferrimagnetic Pt/Co/Tb bubble domains

We examine the laser-assisted electron-positron pair-creation process from the quantum vacuum in the presence of a binding potential with one optically active bound electron. If this core electron is initially prepared in a coherent superposition state of two resonant bound states, the electronic phase properties between both state excitations can be transferred to the positron during the pair-creation process. For example, the periodic Rabi population exchange between both electronic states modulates the temporal growth of the pair-creation probability and also leads to an Autler-Townes split positron energy spectra. Even more astonishing, for the case of different phases, for which the internal electronic dynamics (in the absence of pair creation) is identical, the positron's creation probability is different, suggesting that the vacuum decay process can ``sense'' the phase and not just the occupation number of the core electron. The field theoretical model of the laser assisted pair-creation process with subsequent electron capture can be mapped exactly onto two mutually independent (single-electron) ionization-like processes. This mathematical equivalency permits us to derive analytical solutions for the time evolution of the vacuum decay process under the rotating-wave approximation. 

Control of the laser-induced vacuum decay by electronic phases

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Dan-Dan Su

Author Tools

Chat about Author

Papers

Local entanglement entropy at the mott metal-insulator transition in infinite dimensions

Probing the spatial structure of the Dirac vacuum via phase-controlled colliding laser pulses

High-field magnetization and magnetodielectric effect in a Ni2NbBO6 single crystal

Chiral morphology in ferrimagnetic Pt/Co/Tb bubble domains

Control of the laser-induced vacuum decay by electronic phases