Message-passing and stochastic architectures for nanophotonic information processing

Dmitri Pavlichin (Stanford University)

SYSTEMS AND CONTROL SERIES Quantum Technology

DATE: 2013-05-10
TIME: 11:00:00 - 12:00:00
LOCATION: RSISE Seminar Room, ground floor, building 115, cnr. North and Daley Roads, ANU
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ABSTRACT:
Ongoing progress in the design and fabrication of nanoscale optical devices points to their potential for performing logic and latching at very low switching energies (sub-femotojoule). Concurrently, theoretical and computational tools have been developed for modeling the dynamics of quantum optical systems operating in the few-photon regime. These developments present an opportunity to consider the computational potential of such systems and to search for a computational setting that naturally accommodates noisy, low-power components interacting via optical coherent fields.

We present simple nanophotonic constructions of several useful systems, including a photonic binary multiplier, register, and clock circuit. Further, we suggest that photonic systems interacting through coherent fields are natural candidates for the emulation of iterative and stochastic algorithms involving propagation of information around a graph - used today for error-correction, probabilistic inference, optimization, and other signal-processing tasks. We make this analogy concrete by describing a photonic circuit design for iterative decoding of a class of low density parity check (LDPC) codes used for communication across a noisy channel. Extensions to related settings, like message-passing and factor graph algorithms, are discussed.
BIO:
Dmitri Pavlichin is a graduate student in the Physics Department at Stanford University in Hideo Mabuchi's group. Dmitri's work is focused on physical and statistical modeling of quantum optical systems and circuits for information processing. He also works on applications of information theory and statistical signal processing to the single-molecule biophysics work in Hideo Mabuchi's group.