ITAMP Topical Lunch Discussion
Date: Thursday, March 3rd
Time:
12:00-1:30 pm
Pizza will be served.
Location: B-106 @ Center for Astrophysics (60
Garden Street)
Directions: after entering the lobby of the CfA, turn
right to enter the hallway of the B building. In the
hallway, turn right again, and B-106 is there.
Speaker:
Robert Fickler
(University of Ottawa)
Title: Twisted
Photon Entanglement with 10010 Quanta and over large Distances
Abstract:
Photons with twisted phase-fronts can carry an (theoretically)
unbounded amount of orbital angular momentum (OAM), which
corresponds to a large state space for encoding quantum
information. They can be used as laboratory realization of
high-dimensional quantum states, which are known to be
advantageous in quantum information schemes, e.g. quantum
cryptography. Additionally, twisted photons are of fundamental
interest to test how much information a single quantum system
can carry, how large the dimensionality of entanglement can be
or to challenge possible limits of quantum mechanical
predictions.
In a first experiment, we investigate the latter one by
exploring how many quanta of orbital angular momentum an
entangled photon pair allows. We employ a novel technique that
is able to generate photons with unprecedented high quanta of
OAM by reflecting them from a mirror with a surface profile
corresponding to the required helical phase. With this we are
able to entangle up to ±10010 quanta of OAM of one photon with
the polarization of its partner, thereby realizing a quantum
experiment involving the largest quantum number so far (to our
knowledge).
In a second experiment, we investigate the possibility of
distributing OAM entangled photons over long distances.
Despite pessimistic theoretical predictions, we experimentally
demonstrate the successful distribution of entanglement
encoded in OAM through a turbulent intra-city link of 3
kilometers. Here, we are able to verify entanglement of
photons carrying up to ±2 OAM quanta and show the capability
of our setup to distribute at least 11 orthogonal quantum
channels.
--
Dr. Igor Pikovski
Institute for Theoretical Atomic, Molecular and Optical Physics (ITAMP)
Harvard-Smithsonian Center for Astrophysics
60 Garden St, MS-14; Cambridge, MA 02138, USA
Tel.: +1 (617) 496-7613
e-mail: igor.pikovski@cfa.harvard.edu
www.cfa.harvard.edu/~igor.pikovski/