Quantum Frontiers

Dr. Alexander Poddubny

Engineering how photons and atoms talk—turning waveguides, lattices, and time itself into knobs for quantum light

Group website → Email → Google Scholar → Office — to confirm

01 / Research

Research

The group develops the theory of how light interacts with matter when both are confined and strongly coupled, with a particular focus on emitters coupled to one-dimensional photonic channels. In this waveguide QED regime, photons routed along a single mode mediate long-range interactions between atoms, qubits, or quantum dots, giving rise to collective effects that have no counterpart in free space. The aim is to understand, predict, and design these many-body photonic states analytically and numerically, bridging quantum optics, condensed-matter theory, and nanophotonics.

A central theme is the interplay of superradiance and subradiance: ensembles of emitters can radiate cooperatively in bright modes or trap excitations in long-lived dark, subradiant states that are promising for photon storage and quantum information. The group also studies systems whose parameters are modulated in time, where periodic or structured driving opens routes to nonreciprocal transport, photon frequency conversion, and synthetic gauge fields for light. Understanding these phenomena matters for building scalable quantum networks, robust photonic memories, and on-chip devices where single photons are generated, routed, and entangled on demand.

Quantum scattering theoryMaster-equation and Lindblad methodsInput-output formalismTight-binding and lattice modelsFloquet theoryGreen's-function techniques

Waveguide QED and photon transportTheory of single- and few-photon scattering from emitters coupled to one-dimensional waveguides, including bound states, photon-photon correlations, and many-body effects.

Superradiance and subradianceCollective decay in emitter arrays, with emphasis on long-lived subradiant dark states for storing and protecting quantum excitations.

Time-modulated quantum systemsPeriodically and dynamically driven emitters and lattices that enable frequency conversion, synthetic dimensions, and nonreciprocal light transport.

Topological photonicsEngineering protected edge states and chiral light-matter coupling in photonic lattices and arrays of quantum emitters.

Atom and qubit arrays as quantum metamaterialsOrdered ensembles of two-level systems acting as tunable mirrors, lenses, and nonlinear media for individual photons.

02 / People