Squeezed magnons in an optical lattice: Application to simulation of the dynamical Casimir effect at finite temperature

Squeezed Dirac and topological magnons in a bosonic honeycomb optical lattice

“…We study the magnon squeezing of the corresponding quantum spin system in the ferromagnetic and antiferromagnetic phases with a DM SOI, which introduces topological features in the associated magnon dispersions. We show that the squeeze coherent oscillations of magnons in the ferromagnetic phase requires no dipolar interactions [21][22][23]. This is a consequence of the Z 2 symmetry of the Hamiltonian.…”

“…This degeneracy is lifted by a discrete Z 2 anisotropy of the Hamiltonian. For the ferromagnetic phase, the Z 2 symmetry of the Hamiltonian naturally allows an off-diagonal term necessary for magnon squeezing to exist in stark contrast to rotationally symmetric ferromagnets in which a dipolar interaction is required [21][22][23]. In solid-state materials, spontaneous Raman scattering or femtosecond optical pulses measurements in honeycomb antiferromagnetic insulators XPS 3 (X ≡ Mn and Fe) [24][25][26][27] could provide evidence of magnon squeezing similar to those found in the cubic antiferromagnetic insulators XF 2 (X ≡ Mn and Fe) [16,17].…”

“…A possible realization in onedimensional optical lattice which maps to a ferromagnetic spin chain [20] has also been proposed [21]. However, magnon squeezing in ferromagnetic systems necessarily requires a dipolar interaction [21][22][23], which might not be present in some systems. Therefore, it is highly desirable to explore alternative scenarios in which ferromagnetic magnon squeezing can emerge without dipolar interaction and also the possibility of squeezed magnons in other antiferromagnetic insulators such as the honeycomb antiferromagnetic insulators XPS 3 (X ≡ Mn and Fe) [24][25][26][27].…”

“…Recently, squeezed magnons (collective spin-wave excitation) in solid-state materials have garnered much attention [16][17][18][19] as reported in the cubic antiferromagnetic insulators XF 2 (X ≡ Mn and Fe) through the impulsive stimulated Raman scattering [16,17]. A possible realization in onedimensional optical lattice which maps to a ferromagnetic spin chain [20] has also been proposed [21]. However, magnon squeezing in ferromagnetic systems necessarily requires a dipolar interaction [21][22][23], which might not be present in some systems.…”

Quantum phase transitions in networks of Lipkin-Meshkov-Glick models

“…41, the ground state is a product of two-mode squeezed states with squeezing parameters χ k = artanh[ε 1 (k)/ε 0 (k)], where ε 0 (k) and ε 1 (k) are defined in (20). The two-mode squeezing operator [40,41] is…”