Generalized fidelity susceptibility at phase transitions. (6th May 2015)

• Record Type: Journal Article
• Authors: You, Wen-Long; He, Li
• Is Part Of: Journal of physics. Volume 27:Number 20(2015)
• Publication Date: 2015-05-06
• Subjects: generalized fidelity susceptibility -- quantum phase transition -- dynamical structure factor; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/20/205601
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: In the present work, we investigate the intrinsic relation between quantum fidelity susceptibility (QFS) and the dynamical structure factor. We give a concise proof of the QFS beyond the perturbation theory. With the QFS in the Lehmann representation, we point out that the QFS is actually the negative-two-power moment of dynamical structure factor and illuminate the inherent relation between physical quantities in the linear response theory. Moreover, we discuss the generalized fidelity susceptibility (GFS) of any quantum relevant operator, that may not be coupled to the driving parameter, and present similar scaling behaviors. Finally, we demonstrate that the QFS cannot capture the fourth-order quantum phase transition in a spin-1/2 anisotropic XY chain in the transverse alternating field, while a lower-order GFS can seize the criticalities.