Antiferromagnetic Instanton Interference in Magnetic Field

Golyshev, V. Yu.; Popkov, A. F.

doi:10.1209/0295-5075/29/4/010

Cited by 23 publications

(12 citation statements)

References 12 publications

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“…The presence of a magnetic field may also lead to similar effects; this was noted in the analysis of the nonlinear dynamics of antiferromagnets 22 as well as for the MQT effect, see Ref. 22 and recent publications 5,[23][24][25][26][27] .…”

Section: Introductionmentioning

confidence: 72%

“…Some of these ori-entations of the field for orthorhombic antiferromagnets were considered in Ref. 5 . Thus, we arrive at the following conclusions.…”

Section: Lagrangian Of the σ-Model For Real Antiferromagnetsmentioning

confidence: 99%

“…8 No interference effects are observed in pure antiferromagnets (i.e., in the case of complete compensation of the spins of sublattices), but such effects may appear in the applied magnetic field. 5 It will be shown below that even at zero field the interference effects can also appear when the real magnetic symmetry of the crystal is taken into account, in particular, in the presence of the Dzyaloshinskii-Moriya (DM) interaction.…”

Section: Introductionmentioning

confidence: 99%

“…For ferromagnetic particles these effects suppress tunneling for half-integral values of the total spin of the system 3,4 and lead to oscillatory dependences of the tunnel splitting of energy levels on extrinsic parameters. 5 In addition, in contrast to the effects of quantum escape from a metastable to stable state the manifestations of the CMQT effects are not masked by thermal fluctuations.…”

Section: Introductionmentioning

confidence: 99%

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Interference of instanton trajectories during quantum tunneling in small particles of real antiferromagnets

Иванов

Kireev

2002

J. Exp. Theor. Phys.

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For a two-sublattice antiferromagnet the Lagrangian is constructed taking into account Berry phase whose form is matched with the quantum-mechanical Heisenberg Hamiltonian. Tunnel effects are analyzed taking into account the crystallographic symmetry and possible types of Dzyaloshinskii-Moriya interaction. It is shown that, when the real magnetic symmetry and the Dzyaloshinskii-Moriya interaction are taken into consideration, the effects of a destructive instanton interference and the suppression of macroscopic quantum tunneling can play an essential role. It also may lead to a periodic dependence of the ground-state level splitting on the Dzyaloshinskii-Moriya interaction constant; the magnitude of this splitting is calculated.

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Section: Introductionmentioning

confidence: 72%

“…Some of these ori-entations of the field for orthorhombic antiferromagnets were considered in Ref. 5 . Thus, we arrive at the following conclusions.…”

Section: Lagrangian Of the σ-Model For Real Antiferromagnetsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interference of instanton trajectories during quantum tunneling in small particles of real antiferromagnets

Иванов

Kireev

2002

J. Exp. Theor. Phys.

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“…12,13 In this geometry the most interesting effect arises due to the fluctuation determinant. 13,15 The equations for small fluctuations and around the instanton solution are uncoupled again, but a complex-valued potential appears in the equation for .…”

Section: B Field Perpendicular To the Easy Axismentioning

confidence: 99%

Macroscopic quantum tunneling in small antiferromagnetic particles: Effects of a strong magnetic field

Иванов

Kireev

2004

Phys. Rev. B

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We consider an effect of a strong magnetic field on the ground-state and macroscopic coherent tunneling in small antiferromagnetic particles with uniaxial and biaxial single-ion anisotropy. We find several tunneling regimes that depend on the direction of the magnetic field with respect to the anisotropy axes. For the case of a purely uniaxial symmetry and the field directed along the easy axis, an exact instanton solution with two different scales in imaginary time is constructed. For a rhombic anisotropy the effect of the field strongly depends on its orientation: with the field increasing, the tunneling rate increases or decreases for the field parallel to the easy or medium axis, respectively. The analytic results are complemented by numerical simulations.

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