Dear quanta, We are meeting tomorrow at the usual time and place (6-310, 11am). Peter _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

Hello everybody, There will be a group meeting tomorrow at 11:00 in the usual place (6-310). There is nobody currently scheduled for to talk, so if you have anything to tell us, we'll be ready to listen. (And if nobody volunteers, I can say something.) Peter _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

Peter, Did you get my earlier e-mail about possibly giving a talk on Mon., Nov. 20 on additivity violations?? See below. If not, I'd be happy to meet informally with anyone interested either Mon. afternoon or Tues. morning Nov. 21. Beth On Thu, Nov 9, 2017 at 9:52 PM, Peter Shor &lt;shor(a)math.mit.edu&gt; wrote: ---------- Forwarded message ---------- From: Beth Ruskai &lt;mbruskai(a)gmail.com&gt; Date: Mon, Nov 6, 2017 at 9:04 AM Subject: special seminar To: Isaac Chuang &lt;ichuang(a)mit.edu&gt;du>, Peter Shor &lt;shor(a)math.mit.edu&gt; Cc: slloyd(a)mit.edu, aram harrow &lt;aram(a)mit.edu&gt; Dear Peter, Aram, Ike and Seth, I will be in the Boston area Nov. 20 and 21 and wonder if they would be any interest in -- and enough people around -- for a special seminar on the topic below. My current plan is to fly in Mon. morning on an early flight. So Mon. afternoon would work best for me. However, late Mon. morning would also work. Tues. morning I am free, but would need to leave by noon. Beth Title: Using local additivity to find examples of superadditivity of quantum channels. Speaker: Mary Beth Ruskai Abstract: The local additivity of minimal output entropy can be extended to local additivity of maximal relative entropy with respect to a fixed reference state. This can be exploited to test channels for superadditivity of Holevo capacity with numerical effort comparable to searching for the minimal output entropy. Local maxima which do not arise from product inputs play a key role. Moreover, evidence of superadditivity can be found even if the additivity violation itself is too small to be seen numerically. This talk will be divided into two parts. First we sketch the Gour-Friedland proof of local additivity with several significant simplifications. Second, we describe a program to test 3-state qubit channels for superadditivity of the Holevo capacity. ************************************************************ ***************** Mary Beth Ruskai ruskai(a)member.ams.org 710 Wake Robin Dr. mruskai(a)uvm.edu Shelburne, VT 05482 http://mbruskai.info/ cell +1 802 829 0085 <(802)%20829-0085> text OK, but no voice mail: internet +1 802 489 4954 <(802)%20489-4954> can get messages. Emeritus Professor of Mathematics, University of Massachusetts Lowell Research Professor, Tufts University (2003-2013) Associate Member, Institute for Quantum Computing, Waterloo, Canada (2012-2016) Research Affiliate, University of Vermont _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip