[quantum-info] PIQuDos today 4pm time room

[Roger Colbeck]

Hi all,

Today we have a talk by Steve Flammia, details below.

Best wishes,

Roger

Title: Verification and Characterization of Quantum States and Processes
Speaker(s): Steve Flammia - University of Washington
Abstract: Recent years have witnessed tremendous progress in laboratory 
experiments which prepare highly entangled states of quantum many-body 
systems. As the complexity of these states increases, however, so too 
does the difficultly in verifying the quality of the experiment by some 
objective measure and in characterizing any undesired noise processes. 
In this talk I will discuss several new methods which address both tasks 
-- verification and characterization -- using far fewer resources than 
traditional methods. I will begin by discussing compressive sensing, a 
result from classical signal processing which can drastically reduce the 
required number of samples to reconstruct the spectrum of a 
time-dependent signal. By adapting and extending these methods to the 
setting of quantum mechanical systems, I will show how to verify and 
characterize a broad class of quantum experiments using quadratically 
fewer measurement settings than traditional methods, an improvement 
which is provably optimal. Next, I will show how ideas from quantum 
information theory and condensed matter physics allow us to efficiently 
reconstruct the ground state of any local Hamiltonian of a gapped 
one-dimensional interacting quantum many-body system. Finally, I will 
show how to directly verify the quality of any experiment which prepares 
a pure quantum state using only a constant number of measurement 
settings, independent of the size of the system.
Date: 11/01/2012 - 4:00 pm
Series: Perimeter Institute Quantum Discussions
Location: Time Rm