BEGIN:VCALENDAR VERSION:2.0 PRODID:Data::ICal 0.22 BEGIN:VEVENT DESCRIPTION:Ramis Movassagh\, IBM\n\n
\n Entanglement is a \;quantum& nbsp\;correlation which does not appear classically\, and it serves as a r esource for \;quantum \;technologies such as \;quantum \;c omputing. The \;area \;law \;says that the amount of entanglem ent between a subsystem and the rest of the system is proportional to the& nbsp\;area \;of the boundary of the subsystem and not its volume. A sy stem that obeys an \;area law \;can be simulated more efficiently than an arbitrary \;quantum \;system\, and an \;area \;law provides useful information about the low-energy physics of the system. It was widely believed that the \;area \;law \;could not be viol ated by more than a logarithmic factor (e.g. based on critical systems and ideas from conformal field theory) in the system&rsquo\;s size. We introd uce a class of exactly solvable one-dimensional models which we can prove have exponentially more entanglement than previously expected\, and violat e the \;area \;law \;by a square root factor. \; We also p rove that the gap closes as n^{-c}\, where c \\ge 2\, which rules out conf ormal field theories as the continuum limit of these models. It is our hop e that the mathematical techniques introduce herein will be of use for sol ving other problems.
\n\n (Joint \;work \;with \;Peter&n bsp\;Shor).
\n\n  \;
\n\n References:
\n\n Phys. Rev . Lett. 109\, 207202 \;
\n\n http://arxiv.org/abs/1408.1657
\n\n  \ ;
\n DTSTART:20151001T193000Z LOCATION:Physics Building\, Room 204 SUMMARY:A counterexample to the area law for quantum matter END:VEVENT END:VCALENDAR