Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2010-10-21
Phys. Rev. B 83, 075118 (2011)
Physics
Condensed Matter
Statistical Mechanics
12 pages, 9 figures
Scientific paper
10.1103/PhysRevB.83.075118
We study scaling behavior of the geometric tensor $\chi_{\alpha,\beta}(\lambda_1,\lambda_2)$ and the fidelity susceptibility $(\chi_{\rm F})$ in the vicinity of a quantum multicritical point (MCP) using the example of a transverse XY model. We show that the behavior of the geometric tensor (and thus of $\chi_{\rm F}$) is drastically different from that seen near a critical point. In particular, we find that is highly non-monotonic function of $\lambda$ along the generic direction $\lambda_1\sim\lambda_2 = \lambda$ when the system size $L$ is bounded between the shorter and longer correlation lengths characterizing the MCP: $1/|\lambda|^{\nu_1}\ll L\ll 1/|\lambda|^{\nu_2}$, where $\nu_1<\nu_2$ are the two correlation length exponents characterizing the system. We find that the scaling of the maxima of the components of $\chi_{\alpha\beta}$ is associated with emergence of quasi-critical points at $\lambda\sim 1/L^{1/\nu_1}$, related to the proximity to the critical line of finite momentum anisotropic transition. This scaling is different from that in the thermodynamic limit $L\gg 1/|\lambda|^{\nu_2}$, which is determined by the conventional critical exponents. We use our results to calculate the defect density following a rapid quench starting from the MCP and show that it exerts a step-like behavior for small quench amplitudes. Study of heat density and diagonal entropy density also show signatures of quasi-critical points.
Dutta Amit
Mukherjee Victor
Polkovnikov Anatoli
No associations
LandOfFree
Oscillating fidelity susceptibility near a quantum multicritical point does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Oscillating fidelity susceptibility near a quantum multicritical point, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oscillating fidelity susceptibility near a quantum multicritical point will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-423462