Doping a Correlated Band Insulator: A New Route to Half-Metallic Behavior

Garg, Arti; Krishnamurthy, H. R.; Randeria, Mohit

doi:10.1103/physrevlett.112.106406

Cited by 33 publications

(52 citation statements)

References 29 publications

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“…Nowadays, thanks to modern synthesis technology, epitaxial strain could be introduced in the sample processing on purpose. Electron/hole doping is another implementable solution for band modification, and the formation of HM state as in Garg's study is a remarkable achievement. As a matter of fact, electron/hole doping usually occurs between interfaces or during exfoliation for 2D materials.…”

Section: Magnetic Moment (μB) For Cri3 Monolayer From Gga+u (Ucr = 5mentioning

confidence: 99%

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer

Gao

Wang

et al. 2018

Physica Rapid Research Ltrs

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CrI3 single layer, as a two‐dimensional magnet, is of great interest for next generation ultra‐thin spintronics. In this letter, based on first principles calculation, the electronic structure and magnetic behavior of CrI3 single layer are studied. The extremely strong Cr 3d–I 5p hybridization, which is responsible for the exceptional ferromagnetic behavior and the highest magnetic ordering temperature among the CrX3 (X = Cl, Br, I) family, can be ascribed to the impetuous covalency of iodine. An insulator to half metal transition can be regulated by the strategy to form a Cr defect in the pristine monolayer and this unique electron state is independent of the defect concentration and the value of electron correlation. Meanwhile, the half metal becomes an itinerant ferromagnet mediated by I 5p conduction electron, a potential candidate for real application.

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Section: Magnetic Moment (μB) For Cri3 Monolayer From Gga+u (Ucr = 5mentioning

confidence: 99%

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer

Gao

Wang

et al. 2018

Physica Rapid Research Ltrs

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“…Perhaps the simplest model in which one can carry out this exploration is an extension of the Hubbard model, known as the Ionic Hubbard model (IHM), with a staggered on-site "ionic" potential ∆ added in. In the recent past the IHM has been studied in various dimensions by a variety of numerical and analytical tools [1][2][3][4][5][6][7][8][9][10][11][12][13]. In one-dimension [1][2][3] it has been shown to have a spontaneously dimerized phase, in the intermediate coupling regime, which separates the weakly coupled band insulator from the strong coupling Mott insulator.…”

Section: Introductionmentioning

confidence: 99%

Phase diagram of the half-filled ionic Hubbard model

2015

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We study the phase diagram of the ionic Hubbard model (IHM) at half-filling on a Bethe lattice of infinite connectivity using dynamical mean field theory (DMFT), with two impurity solvers, namely, iterated perturbation theory (IPT) and continuous time quantum Monte Carlo (CTQMC). The physics of the IHM is governed by the competition between the staggered ionic potential ∆ and the on-site Hubbard U . We find that for a finite ∆ and at zero temperature, long range antiferromagnetic (AFM) order sets in beyond a threshold U = UAF via a first order phase transition. For U smaller than UAF the system is a correlated band insulator. Both the methods show a clear evidence for a quantum transition to a half-metal phase just after the AFM order is turned on, followed by the formation of an AFM insulator on further increasing U . We show that the results obtained within both the methods have good qualitative and quantitative consistency in the intermediate to strong coupling regime at zero temperature as well as at finite temperature. On increasing the temperature, the AFM order is lost via a first order phase transition at a transition temperature TAF (U, ∆) (or, equivalently, on decreasing U below UAF (T, ∆)), within both the methods, for weak to intermediate values of U/t. In the strongly correlated regime, where the effective low energy Hamiltonian is the Heisenberg model, IPT is unable to capture the thermal (Neel) transition from the AFM phase to the paramagnetic phase, but the CTQMC does. At a finite temperature T , DMFT+CTQMC shows a second phase transition (not seen within DMFT+IPT) on increasing U beyond UAF . At UN > UAF , when the Neel temperature TN for the effective Heisenberg model becomes lower than T , the AFM order is lost via a second order transition. For2 ) where x = 2∆/U and thus TN increases with increase in ∆/U . In the 3-dimensional parameter space of (U/t, T /t and ∆/t), as T increases, the surface of first order transition at UAF (T, ∆) and that of the second order transition at UN (T, ∆) approach each other, shrinking the range over which the AFM order is stable. There is a line of tricritical points that separates the surfaces of first and second order phase transitions.

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“…In addition, competition between two interactions can close and suppress the energy gap [2]. For studying the opening and suppression of energy gap in spectrum of a honeycomb lattice, we started with a simple tight binding Hamiltonian, which the substrate can induce a symmetry breaking through an ionic potential of strength ∆ and adding on-site repulsive interaction U [3].…”

Section: Introductionmentioning

confidence: 99%

Effects of correlations on honeycomb lattice in ionic-Hubbard model

2015

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In a honeycomb lattice the symmetry has been broken by adding an ionic potential and a single-particle gap was generated in the spectrum. We have employed the iterative perturbation theory (IPT) in dynamical mean field approximation method to study the effects of competition between U and ∆ on energy gap and renormalized Fermi velocity. We found, the competition between the single-particle gap parameter and the Hubbard potential closed the energy gap and restored the semi-metallic phase, then the gap is opened again in Mott insulator phase. For a fixed ∆ by increasing U , the renormalized Fermi velocityṽ F is decreased, but change in ∆, for a fixed U , has no effects onṽ F . The difference in filling factor is calculated for various number of U, ∆. The results of this study can be implicated for gapped graphene e.g. hydrogenated graphene.

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Doping a Correlated Band Insulator: A New Route to Half-Metallic Behavior

Cited by 33 publications

References 29 publications

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer

Phase diagram of the half-filled ionic Hubbard model

Effects of correlations on honeycomb lattice in ionic-Hubbard model

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Doping a Correlated Band Insulator: A New Route to Half-Metallic Behavior

Cited by 33 publications

References 29 publications

On the Ferromagnetism and Band Tailoring of CrI3 Single Layer

On the Ferromagnetism and Band Tailoring of CrI3 Single Layer

Phase diagram of the half-filled ionic Hubbard model

Effects of correlations on honeycomb lattice in ionic-Hubbard model

Contact Info

Product

Resources

About

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer

On the Ferromagnetism and Band Tailoring of CrI₃ Single Layer