mps-0.0.0
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itebd_string_order_z.cc
1 // -*- mode: c++; fill-column: 80; c-basic-offset: 2; indent-tabs-mode: nil -*-
2 /*
3  Copyright (c) 2012 Juan Jose Garcia Ripoll
4 
5  Tensor is free software; you can redistribute it and/or modify it
6  under the terms of the GNU Library General Public License as published
7  by the Free Software Foundation; either version 2 of the License, or
8  (at your option) any later version.
9 
10  This program is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  GNU Library General Public License for more details.
14 
15  You should have received a copy of the GNU General Public License along
16  with this program; if not, write to the Free Software Foundation, Inc.,
17  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19 
20 #include <mps/flags.h>
21 #include "slow_expected.hpp"
22 #include "bdry_expected.hpp"
23 #include "canonical_expected.hpp"
24 
25 namespace mps {
26 
27  cdouble
29  const CTensor &Opi, int i, const CTensor &Opmiddle,
30  const CTensor &Opj, int j)
31  {
33  return do_string_order(psi, Opi, i, Opmiddle, Opj, j);
34  } else if (FLAGS.get(MPS_ITEBD_EXPECTED_METHOD) == MPS_ITEBD_SLOW_EXPECTED){
35  return slow_string_order(Opi, i, Opmiddle, Opj, j,
36  psi.matrix(0), psi.right_vector(0),
37  psi.matrix(1), psi.right_vector(1));
38  } else {
39  return bdry_string_order(Opi, i, Opmiddle, Opj, j,
40  psi.matrix(0), psi.right_vector(0),
41  psi.matrix(1), psi.right_vector(1));
42  }
43  }
44 
45 }
const Tensor & matrix(int site) const
Return the matrix for the lattice 'site'.
Definition: itebd.h:88
const Tensor & right_vector(int site) const
Return the vector to the right of this site.
Definition: itebd.h:103
double string_order(const RiTEBD &psi, const RTensor &Opi, int i, const RTensor &Opmiddle, const RTensor &Opj, int j)
String order parameter between sites 'i' and 'j', both included.
const unsigned int MPS_ITEBD_SLOW_EXPECTED
iTEBD expectation values computing powers of transfer matrices.
Definition: flags.cc:59
An infinite Matrix Product State with translational invariance but using two tensors: one for odd and...
Definition: itebd.h:41
const unsigned int MPS_ITEBD_EXPECTED_METHOD
iTEBD expectation value method selector.
Definition: flags.cc:61
const unsigned int MPS_ITEBD_CANONICAL_EXPECTED
iTEBD expectation values assuming canonical form.
Definition: flags.cc:58