toolbox/makechi

Introduction

The makechi code is often used to deal with the spin-spin correlation function (in imaginary time). It can output the magnetic susceptibility and effective magnetic moment. So far only the GARDENIA and NARCISSUS codes can build the spin-spin correlation function in imaginary time space. If the spin-spin correlation function is in frequency space, this code can not be used directly.

Spin-spin correlation function $\chi_{\text{spin}}(\tau)$:

$$\chi_{\text{spin}}(\tau) = \langle S_z(0) S_z(\tau)\rangle$$

Magnetic susceptibility $\chi_{\text{loc}}$:

$$\chi_{\text{loc}} = \int^{\beta}_0 d\tau \chi_{\text{spin}}(\tau)$$

Effective local magnetic moment $M_e$:

$$M_e = \sqrt{T\chi_{\text{loc}}}$$

Usage

$ ./mchi

Input

• See the terminal prompt
• solver.schi.dat (necessary)

Output

See the terminal output.

Comment

N/A