PairHop file

This file determines the coefficients of the pair-hopping couplings given by

(2.8)\[\mathcal{H} = \sum_{i,j}J_{ij}^{\rm Pair} (c_ {i \uparrow}^{\dagger} c_{j\uparrow}^{\phantom{\dagger}} c_{i \downarrow}^{\dagger} c_{j \downarrow}^{\phantom{\dagger}} + \textit{h.c.}) .\]

An example of the file format is presented below.

======================
NPairhop 6
======================
========Pairhop ======
======================
   0     1  0.50000
   1     2  0.50000
   2     3  0.50000
   3     4  0.50000
   4     5  0.50000
   5     0  0.50000

File format

• Line 1: Header

• Line 2: [npairhop] [count]

• Lines 3-5: Header

• Lines 6-: [i] [j] [val]

Parameters

• [npairhop]

  Type : String (blank is not allowed)

  Description : An arbitrary keyword for the total number of the pair-hopping couplings.

• [count]

  Type : Integer (blank is not allowed)

  Description : An integer giving the total number of the pair-hopping couplings.

• [i], [j]

  Type : Integer (blank is not allowed)

  Description : An integer giving a site index (\(0 \le i, j < {\rm Nsite}\)).

• [val]

  Type : Float (blank is not allowed)

  Description : A value for \(J_{ij}^{\rm Pair}\).

Usage rules

• Headers cannot be omitted.

• The program is terminated with error if there are duplicated entries.

• The program is terminated with error when the number of entries is different from [count].

• The program is terminated with error if [i] or [j] are outside the range of the defined values.