Tuning of the Berry curvature in 2D perovskite polaritons

Abstract

Topological physics and in particular its connection with artificial gauge fields is a forefront topic in different physical systems, ranging from cold atoms to photonics and more recently semiconductor dressed exciton-photon states, called polaritons. Engineering the energy dispersion of polaritons in microcavities through nanofabrication or exploiting the intrinsic material and cavity anisotropies has demonstrated many intriguing effects related to topology and emergent gauge fields. Here, we show that we can control the Berry curvature distribution of polariton bands in a strongly coupled organic-inorganic 2D perovskite single crystal. The spatial

Electrically tunable Berry curvature and strong light-matter coupling in birefringent perovskite microcavities at room temperature

“…Second, the reduced symmetry of the cavity structure is found to open a gap at polaritonic diabolical points corresponding to Dirac cones in the cavity dispersion relation. This allows us to engineer local concentrations of Berry curvature that can be controlled through applied external voltage which has only been possible using external magnetic fields or temperature variations [28]. The importance of the Berry curvature dipole to the quantum nonlinear Hall effect [57] and rectification in polar semiconductors [58] was recently stressed in a study demonstrating its electric tunability in a monolayer WTe 2 [59].…”

“…Synthesizing polaritonic Berry curvature in optical cavities is a challenging task since it requires breaking of time-reversal symmetry through external magnetic fields acting on the excitonic component [11,28,40,41], or nonzero optical activity for the photons [42]. Such chiral terms open a gap at the diabolical points in the polariton dispersion, corresponding to a Dirac cone intersection [12,44,53,54], where the TE-TM SOC field from Ŝ and the uniform field ∆ HV cancel each other out.…”

“…5e and clearly demonstrate electric tunability of the band geometry in our system. The polaritonic Berry curvature in our system is tunable in a continuous manner with the amplitude of external voltage, rather than magnetic field or temperature [28].…”

“…They combine small effective photonic mass (∼ 10 −5 of the electron mass) with strong nonlin-ear effects [27] and sensitivity to external fields provided by their excitonic matter component. Moreover, they present an unique opportunity over photonic systems to study nontrivial band geometry with formation of Berry curvature [11,28] and topological effects [29][30][31][32][33].…”

“…Recently, photonic analogue of the electronic Dresselhaus [36], and Rashba-Dresselhaus [37,38] SOCs have been realized in microcavities. For the case of cavities that host both Rashba-Dresselhaus (RD) SOC and TE-TM splitting it has been shown theoretically that reducing the cavity symmetry could form local concentrations of Berry curvature [39] without the need to break time reversal symmetry through external magnetic fields acting on the excitonic component of polaritons [11,40,41] or nonzero optical activity for the photons [28,42].…”