A recently-published paper by Army Research Laboratory Scientist Dr. Fredrik Fatemi was chosen as “Editor’s Pick” in the journal Optics Letters.
The paper, “Dynamics of trapped atoms around an optical nanofiber probed through polarimetry,” appears in Opt. Lett. 42, 2283 (2017), and describes a method for measuring potential energy surfaces in atoms near optical nanofibers. This work will facilitate quantum memories and components for quantum networks, said Fatemi. Dr. Fatemi collaborated with the Joint Quantum Institute as part of ARL’s Center for Distributed Quantum Information.
Optical fibers guide light through thin strands of glass and form the backbone of many communications systems. Normally, the guided light is confined entirely in the glass and cannot be measured or sampled except at the fiber input and output. However, by thinning the fiber to a diameter smaller than the wavelength of light, the propagating light cannot be fully confined by the “nanofiber,” leading to an evanescent field outside the fiber that can interact with the nearby, surrounding medium. Such optical nanofibers are an example of a “light-matter interface,” enabling controlled interactions between lasers and atoms or other materials.
He said light-matter interfaces are important ingredients for technologies relying on quantum information science. “Quantum memories, or long-term storage of quantum information, are needed for many of these technologies including unconditionally secure communications over long distance, quantum computing, and distributed, quantum-enhanced sensing. Because much of QIS involves manipulating single photons – the carriers of quantum information – and because quantum information cannot be amplified, minimization of losses is a prerequisite to the increased performance gains.”
He said one of the outstanding challenges of quantum technologies is the creation, manipulation, and control of efficient light-matter interfaces. “By controlling the exact dimensions of the nanofiber, the evanescent field can be very strong such that any nearby atoms are guaranteed to absorb the propagating light. To do this reliably and reproducibly, propagating laser beams are used to hold the atoms in optical traps within 100-200 nanometers from the fiber surface.” Dr. Fatemi’s work describes a method for accurately measuring the traps that hold these atoms.
This research aligns with the Army’s focus on the future forces and priorities to build critical knowledge specifically in quantum technologies that could benefit the warfighter.
Filed Under: Aerospace + defense