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Title: First-principles-based Method For Electron Localization: Application To Monolayer Hexagonal Boron Nitride.
Creator: Ekuma, C. E., Dobrosavljevic, V., Gunlycke, D.
Abstract/Description: We present a first-principles-based many-body typical medium dynamical cluster approximation and density function theory method for characterizing electron localization in disordered structures. This method applied to monolayer hexagonal boron nitride shows that the presence of boron vacancies could turn this wide-gap insulator into a correlated metal. Depending on the strength of the electron interactions, these calculations suggest that conduction could be obtained at a boron vacancy...
Show moreWe present a first-principles-based many-body typical medium dynamical cluster approximation and density function theory method for characterizing electron localization in disordered structures. This method applied to monolayer hexagonal boron nitride shows that the presence of boron vacancies could turn this wide-gap insulator into a correlated metal. Depending on the strength of the electron interactions, these calculations suggest that conduction could be obtained at a boron vacancy concentration as low as 1.0%. We also explore the distribution of the local density of states, a fingerprint of spatial variations, which allows localized and delocalized states to be distinguished. The presented method enables the study of disorder-driven insulator-metal transitions not only in h-BN but also in other physical materials.
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Date Issued: 2017-03-10
Identifier: FSU_libsubv1_wos_000396047700006, 10.1103/PhysRevLett.118.106404
Format: Citation

Title: Multiple Crossovers And Coherent States In A Mott-peierls Insulator.
Creator: Najera, O., Civelli, M., Dobrosavljevic, V., Rozenberg, M. J.
Abstract/Description: We consider the dimer Hubbard model within dynamical mean-field theory to study the interplay and competition between Mott and Peierls physics. We describe the various metal-insulator transition lines of the phase diagram and the breakdown of the different solutions that occur along them. We focus on the specific issue of the debated Mott-Peierls insulator crossover and describe the systematic evolution of the electronic structure across the phase diagram. We found that at low intradimer...
Show moreWe consider the dimer Hubbard model within dynamical mean-field theory to study the interplay and competition between Mott and Peierls physics. We describe the various metal-insulator transition lines of the phase diagram and the breakdown of the different solutions that occur along them. We focus on the specific issue of the debated Mott-Peierls insulator crossover and describe the systematic evolution of the electronic structure across the phase diagram. We found that at low intradimer hopping, the emerging local magnetic moments can unbind above a characteristic singlet temperature T*. Upon increasing the interdimer hopping, subtle changes occur in the electronic structure. Notably, we find Hubbard bands of a mix character with coherent and incoherent excitations. We argue that this statemight be relevant formaterials such as VO2 and its signaturesmay be observed in spectroscopic studies, and possibly through pump-probe experiments.
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Date Issued: 2018-01-09
Identifier: FSU_libsubv1_wos_000419615700005, 10.1103/PhysRevB.97.045108
Format: Citation

Title: Shock Waves and Commutation Speed of Memristors.
Creator: Tang, Shao, Tesler, Federico, Marlasca, Fernando Gomez, Levy, Pablo, Dobrosavljevic, V., Rozenberg, Marcelo
Abstract/Description: Progress of silicon-based technology is nearing its physical limit, as the minimum feature size of components is reaching a mere 10 nm. The resistive switching behavior of transition metal oxides and the associated memristor device is emerging as a competitive technology for next-generation electronics. Significant progress has already been made in the past decade, and devices are beginning to hit the market; however, this progress has mainly been the result of empirical trial and error....
Show moreProgress of silicon-based technology is nearing its physical limit, as the minimum feature size of components is reaching a mere 10 nm. The resistive switching behavior of transition metal oxides and the associated memristor device is emerging as a competitive technology for next-generation electronics. Significant progress has already been made in the past decade, and devices are beginning to hit the market; however, this progress has mainly been the result of empirical trial and error. Hence, gaining theoretical insight is of the essence. In the present work, we report the striking result of a connection between the resistive switching and shock-wave formation, a classic topic of nonlinear dynamics. We argue that the profile of oxygen vacancies that migrate during the commutation forms a shock wave that propagates through a highly resistive region of the device. We validate the scenario by means of model simulations and experiments in a manganese-oxide-based memristor device, and we extend our theory to the case of binary oxides. The shock-wave scenario brings unprecedented physical insight and enables us to rationalize the process of oxygen-vacancy-driven resistive change with direct implications for a key technological aspect-the commutation speed.
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Date Issued: 2016-03-15
Identifier: FSU_libsubv1_wos_000372429900001, 10.1103/PhysRevX.6.011028
Format: Citation

Title: Charge avalanches and depinning in the Coulomb glass: The role of long-range interactions.
Creator: Andresen, Juan Carlos, Pramudya, Yohanes, Katzgraber, Helmut G., Thomas, Creighton K., Zimanyi, Gergely T., Dobrosavljevic, V.
Abstract/Description: We explore the stability of far-from-equilibrium metastable states of a three-dimensional Coulomb glass at zero temperature by studying charge avalanches triggered by a slowly varying external electric field. Surprisingly, we identify a sharply defined dynamical ("depinning") phase transition from stationary to nonstationary charge displacement at a critical value of the external electric field. Using particle-conserving dynamics, scale-free system-spanning avalanches are observed only at the...
Show moreWe explore the stability of far-from-equilibrium metastable states of a three-dimensional Coulomb glass at zero temperature by studying charge avalanches triggered by a slowly varying external electric field. Surprisingly, we identify a sharply defined dynamical ("depinning") phase transition from stationary to nonstationary charge displacement at a critical value of the external electric field. Using particle-conserving dynamics, scale-free system-spanning avalanches are observed only at the critical field. We show that the qualitative features of this depinning transition are completely different for an equivalent short-range model, highlighting the key importance of long-range interactions for nonequilibrium dynamics of Coulomb glasses.
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Date Issued: 2016-03-24
Identifier: FSU_libsubv1_wos_000372712000002, 10.1103/PhysRevB.93.094429
Format: Citation

Title: Strong correlations generically protect d-wave superconductivity against disorder.
Creator: Tang, Shao, Dobrosavljevic, V., Miranda, E.
Abstract/Description: We address the question of why strongly correlated d-wave superconductors, such as the cuprates, prove to be surprisingly robust against the introduction of nonmagnetic impurities. We show that, very generally, both the pair-breaking and the normal state transport scattering rates are significantly suppressed by strong correlations effects arising in the proximity to a Mott insulating state. We also show that the correlation-renormalized scattering amplitude is generically enhanced in the...
Show moreWe address the question of why strongly correlated d-wave superconductors, such as the cuprates, prove to be surprisingly robust against the introduction of nonmagnetic impurities. We show that, very generally, both the pair-breaking and the normal state transport scattering rates are significantly suppressed by strong correlations effects arising in the proximity to a Mott insulating state. We also show that the correlation-renormalized scattering amplitude is generically enhanced in the forward direction, an effect which was previously often ascribed to the specific scattering by charged impurities outside the copper-oxide planes.
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Date Issued: 2016-05-05
Identifier: FSU_libsubv1_wos_000375534600001, 10.1103/PhysRevB.93.195109
Format: Citation

Title: Low-energy Excitations In Quantum Spin Liquids Identified By Optical Spectroscopy.
Creator: Pustogow, A., Saito, Y., Zhukova, E., Gorshunov, B., Kato, R., Lee, T.-H., Fratini, S., Dobrosavljevic, V., Dressel, M.
Abstract/Description: The electrodynamic response of organic spin liquids with highly frustrated triangular lattices has been measured in a wide energy range. While the overall optical spectra of these Mott insulators are governed by transitions between the Hubbard bands, distinct in-gap excitations can be identified at low temperatures and frequencies, which we attribute to the quantum-spin-liquid state. For the strongly correlated ss'-EtMe3Sb[Pd(dmit)(2)](2), we discover enhanced conductivity below 175 cm(-1),...
Show moreThe electrodynamic response of organic spin liquids with highly frustrated triangular lattices has been measured in a wide energy range. While the overall optical spectra of these Mott insulators are governed by transitions between the Hubbard bands, distinct in-gap excitations can be identified at low temperatures and frequencies, which we attribute to the quantum-spin-liquid state. For the strongly correlated ss'-EtMe3Sb[Pd(dmit)(2)](2), we discover enhanced conductivity below 175 cm(-1), comparable to the energy of the magnetic coupling J approximate to 250 K. For omega -> 0, these low-frequency excitations vanish faster than the charge-carrier response subject to Mott-Hubbard correlations, resulting in a dome-shaped band peaked at 100 cm(-1). Possible relations to spinons, magnons, and disorder are discussed.
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Date Issued: 2018-08-03
Identifier: FSU_libsubv1_wos_000440724200014, 10.1103/PhysRevLett.121.056402
Format: Citation

Department of Physics (5)	+ -
National High Magnetic Field Laboratory (4)	+ -

text (6)	+ -
journal article (3)	+ -

Tang, Shao (2)	+ -
Andresen, Juan Carlos (1)	+ -
Civelli, M. (1)	+ -
Dressel, M. (1)	+ -
Ekuma, C. E. (1)	+ -

Fratini, S. (1)	+ -
Gorshunov, B. (1)	+ -
Gunlycke, D. (1)	+ -
Kato, R. (1)	+ -
Katzgraber, Helmut G. (1)	+ -
Lee, T.-H. (1)	+ -
Levy, Pablo (1)	+ -
Marlasca, Fernando Gomez (1)	+ -
Miranda, E. (1)	+ -
Najera, O. (1)	+ -
Pramudya, Yohanes (1)	+ -
Pustogow, A. (1)	+ -
Rozenberg, M. J. (1)	+ -
Rozenberg, Marcelo (1)	+ -
Saito, Y. (1)	+ -
Tesler, Federico (1)	+ -
Thomas, Creighton K. (1)	+ -
Zhukova, E. (1)	+ -
Zimanyi, Gergely T. (1)	+ -

Physical Review B (3)	+ -
Physical Review Letters (2)	+ -
Physical Review X (1)	+ -

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