Efficient quantum light-matter interfaces based on rare-earth atoms in optical microsphere resonators
Abstract
Photonic quantum information systems with low optical losses that are coupled to highlycoherent atomic or atom-like emitters are cr ucial to scaling quantum networks and otherdistributed quantum systems that rely on optics to transmit quantum information. Suchne tworks would enable secure communications, distributed quantum sensing and quantum information processing, and more. We will develop a platform for efficient quantum light-matter interfaces based on rare-earth atom dopants in microscale whisperinggallery mode res onators. We will use this system for quantum memory and single photongeneration, two major enabling technologies for building pract ical and scalable quantumnetworks. Rare-earth atom dopants have many advantages for quantum information applications including extr emely long coherence times, ability to be hosted in a wide variety ofsolid-state hosts, and relatively small spectral diffusion and inhomogeneous distribution.To that end there have been many demonstrations toward efficient, long-lived quantummemory in rare-ear th ensembles. Microscale whispering gallery mode resonators can havesome of the highest quality factors of any resonator platform a vailable. We will use suchresonators to overcome the weak emission in rare-earth atom dopants to both improvethe ability to implem ent ensemble-based quantum memory and to generate single photonsfrom single emitters. The work proposed here consists of three part s.First we will investigate quantum optical properties of erbium and ytterbium atoms incryogenically cooled silica microsphere res onators. We will investigate both erbium, whichhas a telecom optical transition, and ytterbium, which suffers less from various bro adeningmechanisms in amorphous fused silica. We will measure the Purcell enhancement for bothspecies and optimize our resonator fa brication methods. We will also optimize coupling tothe resonator mode via tapered optical fiber.Second we will demonstrate effici ent optical pumping of erbium for quantum memory. Our silica microsphere resonators should exhibit sufficient enhancement of the lig htmatter interaction to efficiently optically pump erbium, a major challenge for erbium-basedquantum memory for telecom photons. We will investigate both preparation of atomicfrequency comb structures and optical spin polarization. We will explore the limits on efficiency and storage time for these quantum memory protocols in our platform.Third we will generate and characterize single photo ns from single dopants. We willuse spectrally isolated individual dopant atoms as sources of single photons. We will characterize t hese photons in terms of their suitability for quantum information applications bymeasuring their purity, indistinguishability, and efficiency. Demonstration of such a singlephoton is an enabling step toward generating single photons entangled with the internal state of the emitter. Efficient generation of such spin-photon entanglement would bea building block for entanglement distribution and generation of multiphoton entangledstates.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2021
- Source ID
- N000142112598
Entities
People
- Elizabeth A Goldschmidt
Organizations
- Office of Naval Research
- United States Navy
- University of Illinois Urbana–Champaign