Topological Transitions in Metamaterials

Abstract

Light-matter interactions can be controlled by manipulating the photonic environment. We uncovered an optical topological transition in strongly anisotropic metamaterials that results in a dramatic increase in the photon density of states-an effect that can be used to engineer this interaction. We describe a transition in the topology of the iso-frequency surface from a closed ellipsoid to an open hyperboloid by use of artificially nanostructured metamaterials. We show that this topological transition manifests itself in increased rates of spontaneous emission of emitters positioned near the metamaterial. Altering the topology of the iso-frequency surface by using metamaterials provides a fundamentally new route to manipulating light-matter interactions.

Broadband enhancement of spontaneous emission from nitrogen-vacancy centers in nanodiamonds by hyperbolic metamaterials

“…In this work, we experimentally study non-resonant broadband enhancement of the emission from NV centers coupled with hyperbolic metamaterials (HMMs). [12][13][14] Our approach takes advantage of the large photonic density of states (PDOS) in a broad range of wavelengths, which is a striking property of HMMs. 15,16 The PDOS, similar to its electronic counterpart, can be quantified as the volume in k-space between isofrequency surfaces…”

Coherence-Driven Topological Transition in Quantum Metamaterials

“…These hyperbolic metamaterials have been harnessed for sub-diffraction imaging [35,36], negative-refraction [30,31], photon density of states engineering [37][38][39], heat transfer [40], and so forth. However, the ability to engineer hyperbolic dispersion at will to harness propagating waves with large wavevectors has been a long sought-after goal.…”

Field-effect induced tunability in hyperbolic metamaterials

“…The latter idea arises from the consideration that Dirac-like dispersion cones can be realized in a linear dispersion regime where the metamaterial effective parameters approach zero, allowing for topological transitions to occur in metamaterials. Hyperbolic metamaterials also support ENZ and epsilon near pole (ENP) spectral regions [1,21] that induce band splitting and support such topological transitions [22]. Thus, active tuning of the effective parameters can tune the spectral regions of topological transitions along with the possibility to dynamically study topological transitions in photonic systems.…”