Summary: QMA/qpoly # PSPACE/poly: De­Merlinizing Quantum Protocols
Scott Aaronson #
University of Waterloo
Abstract
This paper introduces a new technique for removing ex­
istential quantifiers over quantum states. Using this tech­
nique, we show that there is no way to pack an exponential
number of bits into a polynomial­size quantum state, in such
a way that the value of any one of those bits can later be
proven with the help of a polynomial­size quantum witness.
We also show that any problem in QMA with polynomial­
size quantum advice, is also in PSPACE with polynomial­
size classical advice. This builds on our earlier result that
BQP/qpoly # PP/poly, and offers an intriguing counter­
point to the recent discovery of Raz that QIP/qpoly = ALL.
Finally, we show that QCMA/qpoly # PP/poly and that
QMA/rpoly = QMA/poly.
1. Introduction
Let Bob be a graduate student, and let x be an n­bit string
representing his thesis problem. Bob's goal is to learn

Source: Aaronson, Scott - Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT)

Collections: Physics; Computer Technologies and Information Sciences