TY - JOUR
T1 - Black phosphorus plasmonics
T2 - Anisotropic elliptical propagation and nonlocality-induced canalization
AU - Correas-Serrano, D.
AU - Gomez Diaz, Juan Sebastian
AU - Melcon, A. Alvarez
AU - Alù, Andrea
PY - 2016/10/1
Y1 - 2016/10/1
N2 - We investigate unusual surface plasmons polariton (SPP) propagation and light-matter interactions in ultrathin black phosphorus (BP) films, a 2D material that exhibits exotic electrical and physical properties due to its extremely anisotropic crystal structure. Recently, it has been speculated that the ultra-confined surface plasmons supported by BP may present various topologies of wave propagation bands, ranging from anisotropic elliptic to hyperbolic, across the mid- and near-infrared regions of the electromagnetic spectrum. By carefully analyzing the natural nonlocal anisotropic optical conductivity of BP, derived using the Kubo formalism and an effective low-energy Hamiltonian, we demonstrate here that the SPP wavenumber cutoff imposed by nonlocality prohibits that they acquire an arbitrary hyperbolic topology, forcing operation in the canalization regime. The resulting nonlocality-induced canalization presents interesting properties, as it is inherently broadband, enables large light-matter interactions in the very near field, and allows extreme device miniaturization. We also determine fundamental bounds to the confinement of BP plasmons, which are significantly weaker than for graphene, thus allowing a larger local density of states. Our results confirm the potential of BP as a promising reconfigurable plasmonic platform, with exciting applications, such as planar hyperlenses, optoelectronic components, imaging, and communication systems.
AB - We investigate unusual surface plasmons polariton (SPP) propagation and light-matter interactions in ultrathin black phosphorus (BP) films, a 2D material that exhibits exotic electrical and physical properties due to its extremely anisotropic crystal structure. Recently, it has been speculated that the ultra-confined surface plasmons supported by BP may present various topologies of wave propagation bands, ranging from anisotropic elliptic to hyperbolic, across the mid- and near-infrared regions of the electromagnetic spectrum. By carefully analyzing the natural nonlocal anisotropic optical conductivity of BP, derived using the Kubo formalism and an effective low-energy Hamiltonian, we demonstrate here that the SPP wavenumber cutoff imposed by nonlocality prohibits that they acquire an arbitrary hyperbolic topology, forcing operation in the canalization regime. The resulting nonlocality-induced canalization presents interesting properties, as it is inherently broadband, enables large light-matter interactions in the very near field, and allows extreme device miniaturization. We also determine fundamental bounds to the confinement of BP plasmons, which are significantly weaker than for graphene, thus allowing a larger local density of states. Our results confirm the potential of BP as a promising reconfigurable plasmonic platform, with exciting applications, such as planar hyperlenses, optoelectronic components, imaging, and communication systems.
KW - black phosphorus
KW - hyperbolic materials
KW - nonlocality
KW - plasmonics
KW - uniaxial
UR - http://www.scopus.com/inward/record.url?scp=84989857343&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84989857343&partnerID=8YFLogxK
U2 - 10.1088/2040-8978/18/10/104006
DO - 10.1088/2040-8978/18/10/104006
M3 - Article
AN - SCOPUS:84989857343
VL - 18
JO - Journal of Optics (United Kingdom)
JF - Journal of Optics (United Kingdom)
SN - 2040-8978
IS - 10
M1 - 104006
ER -