Entanglement entropy of local operators in quantum Lifshitz theory. (29th September 2016)

• Record Type: Journal Article
• Authors: Zhou, Tianci
• Is Part Of: Journal of statistical mechanics. (2016:Sep.)
• Publication Date: 2016-09-29
• Subjects: Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/2016/09/093106
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: We study the growth of entanglement entropy (EE) of local operator excitation in the quantum Lifshitz model with dynamic exponent z = 2. Specifically, we apply a local vertex operator to the groundstate at a distance l to the entanglement cut and calculate the EE as a function of time for the state's subsequent time evolution. We find that the excess EE compared with the groundstate is a monotonically increasing function which is vanishingly small before the onset at t ∼ l 2 and eventually saturates at a constant value proportional to the scaling dimension of the vertex operator. The quasi-particle picture can interpret the final saturation as the exhaustion of the quasi-particle pairs, while the diffusive nature of the time scale t ∼ l 2 replaces the common causality constraint in CFT calculations. To further understand this property, we compute the excess EE of a small disk probe far from the excitation point and find chromatography patterns in EE generated by quasi-particles of different propagation speeds.