English
Related papers

Related papers: Electronic phase separation in the pyrochlore doub…

200 papers

The exploration of quantum phases in moir\'e systems has drawn intense experimental and theoretical efforts. The realization of honeycomb symmetry has been a recent focus. The combination of strong interaction and honeycomb symmetry can…

Strongly Correlated Electrons · Physics 2024-12-25 Yubo Yang , Miguel A. Morales , Shiwei Zhang

We consider phase separated states in magnetic oxides (MO) thin films. We show that these states have a non-zero electric polarization. Moreover, the polarization is intimately related to a spatial distribution of magnetization in the film.…

Strongly Correlated Electrons · Physics 2019-10-09 O. G. Udalov , I. S. Beloborodov

We present large-scale dynamical simulations of electronic phase separation in the single-band double-exchange model based on deep-learning neural-network potentials trained from small-size exact diagonalization solutions. We uncover an…

Strongly Correlated Electrons · Physics 2021-10-04 Puhan Zhang , Gia-Wei Chern

Spin-state transitions, observed in many transition metal compounds containing Co$^{3+}$ and Fe$^{2+}$, may occur with the change of temperature, pressure, but also with doping, in which case the competition of single-site effects and…

Strongly Correlated Electrons · Physics 2009-07-24 A. O. Sboychakov , K. I. Kugel , A. L. Rakhmanov , D. I. Khomskii

A macroscopic phase separation, in which ferromagnetic clusters are observed in an insulating matrix, is sometimes observed, and believed to be essential to the colossal magnetoresistive (CMR) properties of manganese oxides. The application…

Materials Science · Physics 2011-11-10 R. Mathieu , Y. Tokura

Ultrafast optical excitations allow creating new metastable and hidden states in quantum materials. However, the fundamental material properties required to support new emergent order are largely unknown. Here we show for two colossal…

Strongly Correlated Electrons · Physics 2024-11-21 Tim Titze , Maximilian Staabs , Pia Henning , Karen Stroh , Stefan Mathias , Vasily Moshnyaga , Daniel Steil

The single crystalline form of an insulator, Sr$_3$CuIrO$_{6+\delta}$, is shown to exhibit unexpectedly more than one magnetic transition (at 5 and 19 K) with spin-glass-like magnetic susceptibility behaviour. On the basis of this finding,…

Strongly Correlated Electrons · Physics 2009-11-07 Asad Niazi , P. L. Paulose , E. V. Sampathkumaran

We present our theoretical results on an effective two-band double-exchange model on a pyrochlore lattice for understanding intricate phase competition in Mo pyrochlore oxides. The model includes the twofold degeneracy of $e_g'$ orbitals…

Strongly Correlated Electrons · Physics 2015-05-28 Yukitoshi Motome , Nobuo Furukawa

The phenomenon of colossal magnetoresistance in manganites is generally agreed to be a result of competition between crystal phases with different electronic, magnetic, and structural order; a competition which can be strong enough to cause…

Strongly Correlated Electrons · Physics 2009-11-10 G. C. Milward , M. J. Calderon , P. B. Littlewood

We investigate the ground state properties of electronic models for doped manganites and nickelates. An effective t - J like Hamiltonian is derived from the case of strong Hund coupling between the conduction electrons and localized spins…

Strongly Correlated Electrons · Physics 2009-10-31 Shun-Qing Shen , Z. D. Wang

An analysis of the properties of half-doped manganites is presented. We build up the phase diagram of the system combining a realistic calculation of the electronic properties and a mean field treatment of the temperature effects. The…

Strongly Correlated Electrons · Physics 2009-11-11 Luis Brey

In the present work, low compensated insulating (Ga,Mn)As with 0.7% Mn is obtained by ion implantation combined with pulsed laser melting. The sample shows variable-range hopping transport behavior with a Coulomb gap in the vicinity of the…

We investigate quantum phase transitions for the $s=1/2$ antiferromagnetic Heisenberg model on a pyrochlore lattice. By means of a series expansion starting from isolated tetrahedra, the ground-state phase diagram is determined. When the…

Strongly Correlated Electrons · Physics 2009-10-31 Akihisa Koga , Norio Kawakami

The electronic structure of perovskite manganese oxides is investigated in terms of a Kondo lattice model with ferromagnetic Hund coupling and antiferromagnetic exchange between $t_{2g}$-spins using a finite temperature diagonalization…

Strongly Correlated Electrons · Physics 2009-10-30 Peter Horsch , Janez Jaklic , Frank Mack

From Raman spectroscopy, magnetization, and thermal-expansion on the system La2/3(Ca1-xSrx)1/3MnO3, we have been able to provide a quantitative basis for the heterogeneous electronic model for manganites exhibiting colossal…

Strongly Correlated Electrons · Physics 2009-11-11 F. Rivadulla , M. Otero-Leal , A. Espinosa , A. de Andres , C. Ramos , J. Rivas , J. B. Goodenough

We study the phase diagram of the double exchange model, with antiferromagnetic interactions, in a cubic lattice both at zero and at finite temperature. There is a rich variety of magnetic phases, combined with regions where phase…

Strongly Correlated Electrons · Physics 2009-11-07 J. L. Alonso , J. A. Capitan , L. A. Fernandez , F. Guinea , V. Martin-Mayor

In this report, we study in detail the competitor to the FM metallic state at electronic density $x=1/4$ in the CMR regime using the two-orbital double-exchange model with Jahn-Teller lattice distortions on two-dimensional clusters,…

Materials Science · Physics 2012-01-04 Cengiz Sen , Shuhua Liang , Elbio Dagotto

Phase separation in the Hubbard model is investigated with the dynamical cluster approximation. We find that it is present in the paramagnetic solution for values of filling smaller than one and at finite temperature when a positive…

Strongly Correlated Electrons · Physics 2007-05-23 A. Macridin , M. Jarrell , Th. Maier

In a study of the ferromagnetic phase of a multilayer digital ferromagnetic semiconductor in the mean-field and effective-mass approximations, we find the exchange interaction to have the dominant energy scale of the problem, effectively…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 J. Fernández-Rossier , L. J. Sham

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from…

Materials Science · Physics 2009-11-07 Jordi Marcos , Eduard Vives , Teresa Castan