Coherence-Driven Topological Transition in Quantum Metamaterials

Abstract

We introduce and theoretically demonstrate a quantum metamaterial made of dense ultracold neutral atoms loaded into an inherently defect-free artificial crystal of light, immune to well-known critical challenges inevitable in conventional solid-state platforms. We demonstrate an all-optical control on ultrafast time scales over the photonic topological transition of the isofrequency contour from an open to close topology at the same frequency. This atomic lattice quantum metamaterial enables a dynamic manipulation of the decay rate branching ratio of a probe quantum emitter by more than an order of magnitude. This proposal may lead to practically lossless, tunable and topologically-reconfigurable quantum metamaterials, for single or few-photon-level applications as varied as quantum sensing, quantum information processing, and quantum simulations using metamaterials.

Coherence generating power of unitary transformations via probabilistic average

“…Originating from the fundamental superposition principle of quantum mechanics, quantum coherence is a kind of important quantum resources. It plays key roles in the interference of light, the laser, superconductivity and quantum thermodynamics [1,2,3], as well as in some quantum information tasks [4,5,6,7] and biological processes [8,9,10,11]. However, the rigorous theories of quantum coherence have been proposed only recently [12].…”

Large spontaneous-emission enhancements in metallic nanostructures: towards LEDs faster than lasers [Invited]

“…As a final remark, it should be noted that the large SE-enhancements in antenna nanostructures might also be of interest for creating relatively low-threshold nanolasersexcept that the optimization is, in that case, quite different. Indeed, while overall optical losses are, in a sense, beneficial in designing a good antenna (since the Q-factor of a good antenna should be of the order of unity to allow for good in-/out-coupling of radiation to the antenna), they are disadvantageous for lasers, which require small total (dissipative + radiative) losses for low-threshold operation [4,26,[40][41][42][43]. Here, a key quantity of interest is the fraction of spontaneous emission coupling to the preferred lasing mode -the, so-called, ϐ factor.…”

Strongly coupled cold atoms in bilayer dense lattices

“…Moreover, there is a growing interest in light propagation through a nanometer-size sample of homogeneously broadened (i.e. low-temperature) atoms with a sufficiently high number density due to potential applications in the areas of efficient light transport [2], quantum information processing [3], metamaterials [4], integrated optical devices [5], and nano-optics [6]. Recently realized experiments [7][8][9][10][11] for cold dense atoms motivate theoretical investigations [12][13][14][15][16][17][18][19][20][21][22][23][24] of light propagation at the microscopic level.…”