Dear Friends,
On Thursday, May 9, there will be an ITAMP topical lunch discussion.
Tea Room (P-226) @ CfA (60 Garden Street)
Time: 12:00-1:30
As always pizza will be served.
Speaker: Nathalie de Leon
Title: Quantum optics in the solid state with diamond nanophotonics
Abstract:
Large-scale quantum networks will require efficient interfaces between
photons and stationary quantum bits. Nitrogen vacancy (NV) centers in
diamond are a promising candidate for quantum information processing
because they are optically addressable, have spin degrees of freedom with
long coherence times, and as solid-state entities, can be integrated into
nanophotonic devices. An enabling feature of the NV center is its
zero-phonon line (ZPL), which acts as an atom-like cycling transition that
can be used for coherent optical manipulation and read-out of the spin.
However, the ZPL only accounts for 3-5% of the total emission, and
previously demonstrated methods of producing high densities of NV centers
yield unstable ZPLs.
I will present methods and technologies for gaining both spectral and
spatial control over NV emission by coupling NV centers to nanophotonic
devices. In particular, we have developed a method to create a high-density
device layer of NVs with stable ZPLs in high purity diamond, and have
devised a fabrication scheme to carve single mode waveguides out of the
surface of the bulk diamond substrate. Using this technique, we are able to
fabricate high quality factor, small mode volume photonic crystal cavities
directly out of diamond, and deterministically position these photonic
crystal cavities so that a stable NV center sits at the maximum electric
field. We observe an enhancement of the spontaneous emission at the cavity
resonance by a factor of up to 100. The NV emission is guided efficiently
into a single optical mode, enabling integration with other photonic
elements, as well as networks of cavities, each with their own optically
addressable qubit. These nanophotonic elements in diamond will provide key
building blocks for quantum information processing such as single photon
transistors, enabling distribution of entanglement over quantum networks.
Looking forward to seeing you there,
Misha Lemeshko
--
Dr. Mikhail Lemeshko
Institute for Theoretical Atomic, Molecular, and Optical Physics (ITAMP)
Harvard-Smithsonian Center for Astrophysics MS-14
60 Garden St.
Cambridge, MA 02138
U.S.A.
mlemeshko(a)cfa.harvard.edu
http://sites.google.com/site/mishalemeshko/
Tel. +1 (617) 496-7610
Fax +1 (617) 496-7668