Laser-driven parametric instability and generation of entangled photon-plasmon states in graphene

Abstract

We show that a strong infrared laser beam obliquely incident on graphene can experience a parametric instability with respect to decay into lower-frequency (idler) photons and THz surface plasmons. The instability is due to a strong in-plane second-order nonlinear response of graphene which originates from its spatial dispersion. The parametric decay leads to efficient generation of THz plasmons and gives rise to quantum entanglement of idler photons and surface plasmon states. A similar process can be supported by surface states of topological insulators such as Bi2Se3.

Modeling the excitation of graphene plasmons in periodic grids of graphene ribbons: An analytical approach

“…That foundational publication paved the way for the emergence of many experimental and theoretical works that soon followed, thereby establishing the field of graphene plasmonics [17][18][19][20][21][22][23][24]. As of today, GSPs have been realized in a number of systems, ranging from patterned grids of graphene ribbons [26,27,38,40,[48][49][50][51][52][53], disks [51,[54][55][56][57], and rings [54,55], periodic antidot lattices [57][58][59], resonators [60,61], and hybrid graphenemetal nanoantennas [43,44,[62][63][64], among others [65][66][67][68][69][70][71][72][73][74].…”

“…For extended graphene, these volumes can be about α 3 ≈ 10 −6 times smaller (where α denotes the fine-structure constant) than the volume characterized by the free-space light's wavelength (i.e., λ −3 0 ). Typical strategies to couple light to graphene plasmons involve the patterning of pristine graphene into gratings and related nanostructures [26,27,38,40,[48][49][50][51][51][52][53][54][55][56][57][57][58][59], the use of dielectric gratings [65,66], light scattering from a conductive tip [71][72][73][74], and even nonlinear three-wave mixing [69,70].…”

Purcell enhancement of the parametric down-conversion in two-dimensional nonlinear materials

“…The normalization of functions E ν (r) needs to be chosen in such a way that the commutation relation for boson operatorsĉ ν andĉ ν † have a standard form [ĉ ν ,ĉ ν † ] = δ νν . Following [27][28][29], one can obtain…”

Difference frequency generation of surface plasmon-polaritons in Landau quantized graphene

“…Therefore, its in-plane second-order nonlinear response should be zero in the electric dipole approximation [14]. However, for obliquely incident or in-plane propagating electromagnetic (EM) fields, inversion symmetry is broken by nonzero wavevector components in the plane of graphene, and the secondorder nonlinearity is nonzero and actually quite large [12,13,[15][16][17]. It is enabled by effects of the spatial dispersion, or, in real space, by nonlocal effects beyond the electric dipole approximation.…”

“…It is enabled by effects of the spatial dispersion, or, in real space, by nonlocal effects beyond the electric dipole approximation. A particularly large value of χ (2) equivalent to the bulk value of ∼ 10 −3 m/V per monolayer [13] is reached at low frequencies, for the processes of frequency down-conversion to the terahertz range such as difference frequency generation (DFG) [12,13,[18][19][20] or parametric down-conversion [16].…”