Exciton-Polariton Topological Insulator with an Array of Magnetic Dots

Abstract

Recently there have been several proposals on exciton-polariton topological insulators, most requiring strong external magnetic fields induced by bulky superconducting coils. We propose an alternate design for a polariton topological insulator, where excitons are in a proximity of an additional layer of a ferromagnetic material with a predefined magnetic moment located between the pillars of the cavity. Our design supports a variety of topological phases and transitions between Chern numbers ±2 and ±1 by varying either the magnetic moment of the ferromagnetic material or the spin-orbit coupling between different spin projections, thus enabling compact polariton devices harnessing switchable topological edge modes.

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].…”

Nonlinear optics of coupled nanophotonic reasonators

“…Topological insulators (TIs) have attracted attention in the past decade due to their unique exotic property, namely the appearence of backscattering-immune edge states, which can propagate against perturbation without being backscattered. TIs have been explored in various systems including electronics [199,201], photonics [207,209,210,226,243,244], cold atoms [245], exciton-polaritons [246][247][248][249][250], acoustics [251], etc. In the previous chapter (see sec.…”

Dynamics of light-matter coupled quasiparticles

“…Topological electronic systems with broken time reversal (TR) symmetry [87] are characterized by counter propagating chiral edge states whereas TR invariant topological systems contain a pair of counter propagating helical edge states at each edge corresponding to di↵erent spins states and known as the quantum spin Hall e↵ect [88]. The application of topology in bosonic systems has resulted in creation of one-way transport of photons [90,91,93,[175][176][177], phonons [100,101], excitons [94,178] and exciton-polaritons [94][95][96][97][98][99][179][180][181][182][183]]. Antichiral edge states have been proposed in the modified Haldane model, where modes corresponding to both the edges of a strip flow in the same direction, compensated by the conducting bulk modes that propagate in the opposite direction [186].…”

“…In particular, when photons are coupled to excitons in semiconductor micropillars they hybridize to form exciton-polaritons, which inherit a Zeeman splitting due to their excitonic component when placed in a magnetic field [214]. Since such micropillars can be arranged into lattices it has been possible to form topological polariton systems [183], accounting for the e↵ect of spin-orbit coupling [94][95][96][97][98][99].…”

“…photonics[90][91][92][93], polaritonics[94][95][96][97][98][99], acoustics[100,101], etc. In Fig.1.14 a non-trivial topological band structure for the polaritons is shown.…”