Engineering superradiance using DNA origami
Abstract
Dicke~s model of superradiance, introduced in 1954, described a lasing-like collective behavior of emitterswell before the first l""asers were invented. In the ideal case, superradiance causes a coherently-excitedcluster of N densely-packed light emitting dipoles" to behave as a single giant dipole~one which emitsa pulse of photons whose radiative rate is enhanced by a factor of N and whose i"ntensity is enhancedby N-squared when compared to a single emitter. Since its description, superradiance has been exploredextensiv""ely, both theoretically and experimentally, yielding results relevant to our understanding of lightharvesting complexes in plants,"" to the engineering of new ultrastable light sources, to the construction ofquantum memories and to the metrology of quantum system""s. While the reality of superradiance has beenclearly established, many facets of the phenomena have not been experimentally explor"ed. This is due tothe difficulty of creating high-density well-defined arrangements of emitters at deep subwavelength lengthscales". We propose to use DNA origami to enable the flexible engineering and detailed study of superradiancein two ways: First, we w"ill use DNA origami as a high-resolution breadboard on which light emitters can bearranged into high-density clusters with specific" geometries. Second, we will use DNA origami as an adaptorto interface light emitting clusters with nanophotonic resonators. DNA or"igami is a method that uses a fewhundred short DNA strands to fold a long DNA strand into arbitrary designed 2D and 3D shapes. Eachindividual DNA origami molecule can be used as a scaffold to precisely arrange up to 200 other molecularor nanoparticle components", such as light-emitting organic fluorophores, inorganic lanthanide complexes,or colloidal quantum dots. Further, each DNA origami"" is big enough (100 nanometers across) that its largestfeature, its outline, reaches the length scale accessible by conventional li""thography. Based on this fact, wehave developed a technique to self-assemble DNA origami onto lithographically-defined binding site"s ontoplanar substrates. The method (DNA origami placement) enables us to realize self-assembled nanoarrays ofindividual origami w"here 98% of binding sites are occupied by single origami, the position of the origamiis controlled with the 10 nanometer precision"" of e-beam lithography, and orientation is controlled witha precision of +/-3 degrees. This in turn will allow us to align origami-"templated superradiant clustersprecisely within the modes of microfabricated optical resonators to maximize emitter-resonator coupl"ing,and increase our ability to measure superradiant phenomena for small numbers of emitters.By combining DNA origami and origami"" placement, we will explore the feasibility of engineering superradiance. First, we will create dense ensembles of emitters on" origami (free in solution or within nanophotonicresonators) and to measure an unambiguous signature for superradiance~either emitt"er-number oremitter-density dependent changes in the radiative rate. Second, we will show control over the polarizationof superrad""iance, by controlling the geometry of emitter clusters on the origami. Third, we will demonstratea previously unproposed method for"" engineering the radiative lifetime of emitters, by utilizing DNA origamito position different types of emitters within the same cl"uster: mixing short-lifetime emitters of poor spectralquality with long-lifetime emitters of higher spectral quality may allow us t"o create superradiant pulseswhich are both intense and of higher spectral quality. Further, we will use clusters of mixed emitter-t""ypeto engineer radiative lifetime by a factor of up to a thousand, without the use of an optical resonator. In allproposed experim""ents, our ability to measure and engineer superradiant behavior will be enabled by DNAorigami~s unique ability to control emitter n""umber, density, geometry and type.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2017
- Source ID
- N000141712610
Entities
People
- Paul W. K. Rothemund
Organizations
- California Institute of Technology
- Office of Naval Research
- United States Navy