Holographic entanglement entropy in open-closed string duality

We study minimal co-dimension-2 surfaces in the asymptotically flat background of extremal 3-brane solutions in ten-dimensional type IIB supergravity. A conjectured open-closed string duality combined with the Ryu-Takayanagi prescription implies that the area of the surfaces we consider could be interpreted as the entanglement entropy of a dual (3+1)-dimensional large-N, strongly-coupled open string field theory on D3-branes. As the size of the surface is varied we observe a transition from a volume law to an area law in agreement with expectations from non-locality in an open string field theory. Some of the specifics of this transition bear a qualitative resemblance with the behaviour of holographic entanglement entropy in non-commutative super-Yang-Mills theory.