  This volume contains the proceedings of the 11th International Workshop on
Quantum Physics and Logic (QPL 2014), which was held from the 4th to the 6th of
June, 2014, at Kyoto University, Japan.
  The goal of the QPL workshop series is to bring together researchers working
on mathematical foundations of quantum physics, quantum computing and
spatio-temporal causal structures, and in particular those that use logical
tools, ordered algebraic and category-theoretic structures, formal languages,
semantic methods and other computer science methods for the study of physical
behavior in general. Over the past few years, there has been growing activity
in these foundational approaches, together with a renewed interest in the
foundations of quantum theory, which complement the more mainstream research in
quantum computation. Earlier workshops in this series, with the same acronym
under the name "Quantum Programming Languages", were held in Ottawa (2003),
Turku (2004), Chicago (2005), and Oxford (2006). The first QPL under the new
name Quantum Physics and Logic was held in Reykjavik (2008), followed by Oxford
(2009 and 2010), Nijmegen (2011), Brussels (2012) and Barcelona (2013).
