Photoinduced entanglement in a magnonic Floquet topological insulator

Kar, Satyaki; Basu, B.

doi:10.1103/physrevb.98.245119

Cited by 12 publications

(15 citation statements)

References 59 publications

(64 reference statements)

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“…Such form of exchange can also emerge from the truncated dipolar exchange [15,16]. Furthermore, for α = −1, the antisymmetric form reduces to the DMI, which was first proposed by Dzyaloshinsky and Moriya [17,18] and had attracted continued interest [19][20][21][22][23][24][25]. The DMI has been proved to be a key factor in explaining the magnetic properties in LiMnPO 4 [26], Ni 3 V 2 O 8 [27], MnSi [28,29] and CoFeB [30], etc.…”

Section: Model and Phase Diagrammentioning

confidence: 95%

Lifshitz phase transitions in one-dimensional Gamma model

Liu,

Yi,

Sun

et al. 2020

Preprint

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In this paper, we study quantum phase transitions and magnetic properties of a one-dimensional spin-1/2 Gamma model, which describes the off-diagonal exchange interactions between edge-shared octahedra with strong spin-orbit couplings along the sawtooth chain. The competing exchange interactions between the nearest neighbors and the second neighbors stabilize semimetallic ground state in terms of spinless fermions, and give rise to a rich phase diagram, which consists of three gapless phases. We find distinct phases are characterized by the number of Weyl nodes in the momentum space, and such changes in the topology of the Fermi surface without symmetry breaking produce a variety of Lifshitz transitions, in which the Weyl nodes situating at k = π interchange from type I to type II. A coexistence of type-I and type-II Weyl nodes is found in phase II. The information measures including concurrence, entanglement entropy and relative entropy can effectively signal the second-order transitions. The results indicate that the Gamma model can act as an exactly solvable model to describe Lifshitz phase transitions in correlated electron systems.

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Section: Model and Phase Diagrammentioning

confidence: 95%

Lifshitz phase transitions in one-dimensional Gamma model

Liu,

Yi,

Sun

et al. 2020

Preprint

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“…One of the advantages of the current results is that the photoinduced topological magnons and the chiral edge modes can be tuned by varying the amplitude and polarization of the laser field. Another interesting feature of irradiated Kitaev magnets is that the existence of the Floquet topological magnon insulators does not require the explicit time-reversal symmetry breaking term from the second-order virtual-photon absorption and emission processes, which is mandatory for the existence of Floquet topological states in irradiated graphene [36,37] and irradiated honeycomb ferromagnets [42][43][44]. We also showed that irradiated Kitaev magnets exhibit a tunable photoinduced thermal Hall effect.…”

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confidence: 86%

Photoinduced Floquet topological magnons in Kitaev magnets

Owerre

Mellado

Baskaran

2019

EPL

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We study periodically driven pure Kitaev model and ferromagnetic phase of the Kitaev-Heisenberg model on the honeycomb lattice by off-resonant linearly and circularly-polarized lights at zero magnetic field. Using a combination of linear spin wave and Floquet theories, we show that the effective time-independent Hamiltonians in the off-resonant regime map onto the corresponding anisotropic static spin model, plus a tunable photoinduced magnetic field along the [111] direction, which precipitates Floquet topological magnons and chiral magnon edge modes. They are tunable by the light amplitude and polarization. Similarly, we show that the thermal Hall effect induced by the Berry curvature of the Floquet topological magnons can also be tuned by the laser field. Our results pave the way for ultrafast manipulation of topological magnons in irradiated Kitaev magnets, and could play a pivotal role in the investigation of ultrafast magnon spin current generation in Kitaev materials.Introduction.-Topological band theory of solid-state materials has dominated many aspects of condensedmatter physics over the past decade [1, 2]. The original concept of topological band theory is rooted in insulating electronic systems possessing a nontrivial gap in their energy band structures. They are characterized by the appearance of gapless chiral edge electron modes traversing the bulk gap, which are topologically protected by the Chern number or the Z 2 index of the bulk bands [1, 2].Generally, the concept of topological band structure is independent of the statistical nature of the quasiparticle excitations and therefore is not restricted to insulating electronic systems. Recently, there has been a tremendous interest in the topological properties of spin excitations in insulating quantum magnets. In fact, bosonic topological spin excitations (magnons and triplons) have been studied in many different insulating quantum magnets [3][4][5][6][7][8][9][10][11][12][13][14], and the appearance of chiral edge modes and bulk Chern number have been demonstrated [4][5][6]. Recently, bosonic topological spin excitations mimicking electronic topological insulators have been experimentally observed in kagome ferromagnet Cu(1,3-bdc) [9], dimerized quantum magnet SrCu 2 (BO 3 ) 2 [10], and honeycomb ferromagnet CrI 3 [11].The Mott-insulating honeycomb Kitaev magnets are currently of great interest [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. Candidate Kitaev materials include Na 2 IrO 3 and α-RuCl 3 [26][27][28][29][30]. Recently, topologically protected spin waves have been predicted in the fully-polarized phase of the pure Kitaev model [12] and the Kitaev-Heisenberg model [13] at high magnetic field. In the former, the topological magnons and chiral edge states present in linear spin-wave approximation survive magnon-magnon interactions and therefore are robust [12]. Indeed, the manipulation of topological magnons and magnon spin currents is essential for their practical applications in ultrafast magnetic data s...

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“…In the presence of an intense laser light, electron spin degree of freedom in magnetic insulators can couple to laser field through different processes [48][49][50][51][52][53][54][55][56][57][58]. In particular, quantized spin waves (magnons) are the oscillations of the spin magnetic dipole moment of an electron.…”

Section: Theory Of Laser-irradiated Honeycomb Ferromagnet Crimentioning

confidence: 99%

“…/ ω is the photon emission and absorption term. The first term H 0 is the original time-independent spin Hamiltonian with renormalized interactions J ⊥ ij → J ⊥ ij J 0 (α m ) for S x S x and S y S y couplings, J z ij → J ij for S z S z coupling, and D → DJ 0 (α m ), where J n (x) is the Bessel function of order n. For dominant J 1 interaction, the second term yields a photoinduced DM interaction is of the form [51,[56][57][58]…”

Section: A Light Propagation Along the Z-directionmentioning

confidence: 99%

“…This formalism, however, depends on coupling between the charge degree of freedom and the electric field component of the laser light through the Peierls phase, which result in non-equilibrium Floquet-engineered topological phases. In insulating magnets, the spin degree of freedom can couple to the electric field component of the laser light through different processes [48][49][50][51][52][53][54][55][56][57][58] such as the electric polarization [51] or the Aharonov-Casher phase [59], where the former is encoded in the latter. In this case, the resulting Floquet physics can renormalize the underlying spin Hamiltonian to stabilize magnetic phases and induce Floquet topological spin excitations.…”

Section: Introductionmentioning

confidence: 99%

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Laser-Irradiated CrI$_3$: When Chiral Photons Meet Topological Magnons

Owerre

2018

Preprint

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Insulating honeycomb ferromagnet CrI 3 has recently attracted considerable attention due to its potential use for dissipationless spintronics applications. Recently, topological spin excitations have been observed experimentally in bulk CrI 3 by L. Chen, et al. Phys. Rev. X 8, 041028 (2018) using inelastic neutron scattering. This suggest that bulk CrI 3 has strong spin-orbit coupling and its spin Hamiltonian should include a next-nearest neighbour Dzyaloshinskii-Moriya (DM) interaction.Inspired by this experiment, we study non-equilibrium emergent photon-dressed topological spin and thermal Hall transports in laser-irradiated CrI 3 with and without the DM interaction. We show that the spin excitations can be manipulated into different topological phases with different Chern numbers. Most importantly, we show that the emergent photon-dressed spin and thermal Hall response can be switched to different signs. Hence, the generated magnon spin photocurrents can be manipulated by the laser field, which is of great interest in ultrafast spin current generation and could pave the way for future applications of CrI 3 to topological opto-spintronics and optomagnonics.

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Photoinduced entanglement in a magnonic Floquet topological insulator

Cited by 12 publications

References 59 publications

Lifshitz phase transitions in one-dimensional Gamma model

Lifshitz phase transitions in one-dimensional Gamma model

Photoinduced Floquet topological magnons in Kitaev magnets

Laser-Irradiated CrI$_3$: When Chiral Photons Meet Topological Magnons

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