One-Way Reflection-Free Exciton-Polariton Spin-Filtering Channel

Abstract

We consider theoretically exciton-polaritons in a strip of honeycomb lattice with zigzag edges and it is shown that the interplay among the spin-orbit coupling, Zeeman splitting, and an onsite detuning between sublattices can give rise to a band structure where all the edge states of the system split in energy. Within an energy interval, one of the spin polarized edge states resides with the gap-less bulk having opposite spin. Being surrounded by opposite spin and the absence of the backward propagating edge state ensures both reflection free and feedback suppressed oneway flow of polaritons with one particular spin in the system. The edge states in this system are more localized than those in the standard topological polariton systems and are fully spin polarized. This paves the way for feedback free spin-selective polariton channels for transferring information in polariton networks.

Nonreciprocal Transport of Exciton Polaritons in a Non-Hermitian Chain

“…Apart from the bulky nature of this system, chiral edge states in this scheme appear in counterpropagating pairs, which can cause unwanted feedback. To circumvent this problem, mechanisms to switch off one of the edge states [33], to make both the edge states copropagating [34], or to use the polariton lifetime for input or output isolation [35], have been considered. However, topological schemes remain ultimately inefficient for information transport.…”

Polariton spin jets through optical control

“…In semiconductor microcavities, exciton-polaritons (hereafter polaritons) are characterized by high temperature condensation [5,6], strong nonlinearity, ultrafast spin dynamics [7], and a multitude of optical-based techniques to manipulate their spin state. They offer a promising platform to investigate spin dynamics in extreme condensed matter settings [8][9][10][11][12][13][14][15], and for spinoptronic applications [16][17][18][19][20][21][22].…”

Optically induced topological spin-valley Hall effect for exciton polaritons

“…[23]. Several other theoretical proposals for realizing topological polaritons followed related to the same scheme [45][46][47][48][49][50][51][52][53][54], by using the polarization splitting inside the elliptical micropil-lars [55], by using vortices in staggered honeycomb lattices [56], and by Floquet engineering [57]. Apart from the linear effects, the nonlinearity of polaritons alone can induce topological phases, such as the appearance of the Haldane model [58,59] and antichiral edge states [60].…”