Squeezed thermal spin states of magnons in the ferromagnet

Cheng, Ze; Xu, Bin; Li, Z. M.

doi:10.1140/epjb/e2008-00440-2

Cited by 9 publications

(6 citation statements)

References 18 publications

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“…While coherent states are the most classical states, squeezed states provide prominent examples for nonclassical states. In this context the fluctuation properties of photons have been widely studied [1][2][3], but recently also the fluctuation properties of other boson systems attracted a lot of attention, e.g., atomic Bose-Einstein condensates [4], surface plasmons [5], magnons [6], or phonons [7][8][9][10][11][12][13]. The fluctuation properties of phonons were studied in many different systems including metals and semimetals [7][8][9], perovskite materials [10][11][12], semiconductors [7] as well as high-T C superconductors [13].…”

mentioning

confidence: 99%

Fluctuation properties of phonons generated by ultrafast optical excitation of a quantum dot

Reiter

Wigger

Daniels

et al. 2010

Physica Status Solidi (b)

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In this paper, the fluctuation properties of phonons after the optical excitation of a quantum dot with an ultrashort laser pulse are studied theoretically. When a single pulse with pulse area p creates an exciton in the system, a coherent phonon state builds up. Fluctuations of coherent states are time independent and equal to the vacuum fluctuations. By an excitation with a p/2 pulse a superposition of ground and exciton state is created. In this case the phonon system becomes entangled with the electronic system. In the phonon subsystem this leads to the formation of a statistical mixture of the vacuum and the coherent state. The fluctuations of this mixture oscillate in time with both the single and the double phonon frequency, but never exhibit squeezing. The discrepancies with the predictions made in a Raman tensor model are briefly discussed. All scenarios are illustrated using the Wigner function.

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mentioning

confidence: 99%

Fluctuation properties of phonons generated by ultrafast optical excitation of a quantum dot

Reiter

Wigger

Daniels

et al. 2010

Physica Status Solidi (b)

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“…Magnon squeezed states and quantum spin entanglement are related, and thus they are interesting for applications in quantum computing. In the presence of anisotropy and finite temperature, quantum magnon squeezing is reduced, but here we show that thermal squeezing becomes dominant at finite temperature [72]. This thermal squeezing in uniaxial AF systems, arising from an effective attractive magnon interaction and breaking of the local U(1) symmetry, see equation (20) and discussions below it.…”

Section: Thermal Squeezed Magnonsmentioning

confidence: 58%

“…Interestingly, the eigenmode oscillations become squeezed along y-axis when temperature increases. This effect is a direct consequence of U(1) symmetry breaking arising from nonlinear thermal interactions, see equation (20), and thus is termed thermal squeezed magnons [72], unlike its quantum counterpart defined at T = 0 [67][68][69][70]. In the biaxial AF system the ellipticity, e bi , of μand ν-magnonic eigenmode, are plotted at figure 5 as a function of temperature and momentum.…”

Section: Thermal Squeezed Magnonsmentioning

confidence: 99%

Thermal squeezing and nonlinear spectral shift of magnons in antiferromagnetic insulators

et al. 2022

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We investigate the effect of magnon-magnon interactions on the dispersion and polarization of magnons in collinear antiferromagnetic (AF) insulators at finite temperatures. In two-sublattice AF systems with either uniaxial or biaxial magnetocrystalline anisotropies, we implement a self-consistent Hartree-Fock mean-field approximation to explore the nonlinear thermal interactions. The resulting nonlinear magnon interactions separate into two-magnon intra- and interband scattering processes. Furthermore, we compute the temperature dependence of the magnon bandgap and AF resonance modes due to nonlinear magnon interactions for square and hexagonal lattices. In addition, we study the effect of magnon interactions on the polarization of magnon modes. We find that although the noninteracting eigenmodes in the uniaxial case are circularly polarized, but in the presence of nonlinear thermal interactions the local U(1) symmetry of the Hamiltonian is broken. The attractive nonlinear interactions squeeze the low energy magnon modes and make them elliptical. In the biaxial case, on the other hand, the bare eigenmodes of low energy magnons are elliptically polarized but thermal nonlinear interactions squeeze them further. Direct measurements of the predicted temperature-dependent AF resonance modes and their polarization can be used as a tool to probe the nonlinear interactions. Our findings establish a framework for exploring the effect of thermal magnon interactions in technologically important magnetic systems, such as magnetic stability of recently discovered two-dimensional magnetic materials, coherent transport of magnons, Bose-Einstein condensation of magnons, and magnonic topological insulators.

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“…To eliminate it, several new structures have been reported. [4][5][6][7][8][9][10][11][12][13] In this paper, an SJ-LDMOS with partial lightly doped P pillar (PD) is proposed to suppress the substrate-assisted depletion effect. Owing to the decrease in the charges in the P pillar, the charge balance is achieved and the new peak appearing at the P/P − junction modulates the surface electric field distribution.…”

Section: Introductionmentioning

confidence: 99%

High-voltage super-junction lateral double-diffused metal—oxide semiconductor with a partial lightly doped pillar

Wu¹,

Zhang²,

Fang³

et al. 2013

Chinese Phys. B

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A novel super-junction lateral double-diffused metal—oxide semiconductor (SJ-LDMOS) with a partial lightly doped P pillar (PD) is proposed. Firstly, the reduction in the partial P pillar charges ensures the charge balance and suppresses the substrate-assisted depletion effect. Secondly, the new electric field peak produced by the P/P− junction modulates the surface electric field distribution. Both of these result in a high breakdown voltage (BV). In addition, due to the same conduction paths, the specific on-resistance (Ron,sp) of the PD SJ-LDMOS is approximately identical to the conventional SJ-LDMOS. Simulation results indicate that the average value of the surface lateral electric field of the PD SJ-LDMOS reaches 20 V/μm at a 15 μm drift length, resulting in a BV of 300 V.

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Squeezed thermal spin states of magnons in the ferromagnet

Cited by 9 publications

References 18 publications

Fluctuation properties of phonons generated by ultrafast optical excitation of a quantum dot

Fluctuation properties of phonons generated by ultrafast optical excitation of a quantum dot

Thermal squeezing and nonlinear spectral shift of magnons in antiferromagnetic insulators

High-voltage super-junction lateral double-diffused metal—oxide semiconductor with a partial lightly doped pillar

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