Entanglement in Extended Quantum Systems

In recent years quantum entanglement between the degrees of freedom in different spatial regions has been used to characterise the properties of the ground state of interacting many-body systems. In particular the entanglement entropy is accessible both numerically and in some cases analytically, and exhibits a characteristic scaling behaviour with the size of the subsystem close to a quantum phase transition. For one-dimensional systems this scaling is logarithmic with a universal prefactor, while in higher dimensions the so-called area law holds, with, however, interesting universal correction terms.

In this talk I will try to explain these some of these results and methods in a non-technical manner.