Transport in a quantum point contact (QPC) can be used to generate many-body entanglement of Fermi seas in the leads. A universal relation is found between the generated entanglement entropy and the fluctuations of electric current, which is valid for any protocol of driving the QPC. This relation offers a basis for direct electric measurement of entanglement entropy. In particular, by utilizing space-time duality of 1D systems, we relate electric noise generated by opening and closing the QPC periodically in time with the seminal $\mathcal{S}=\frac{1}{3}\log L$ prediction of conformal field theory.

• Received 10 June 2008

DOI:https://doi.org/10.1103/PhysRevLett.102.100502