Add subcommand to project onto all basis states (only implemented for…

… Spin 1/2 at the moment).
f-koehler · Jul 13, 2022 · 20f2247 · 20f2247
1 parent 4896198
commit 20f2247
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Showing 5 changed files with 111 additions and 0 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -115,6  115,7 @@ mpskit_link_libraries(itensor)
 
 add_library(mpskit_common STATIC
     mpskit/cmd/dmrg.cpp
     mpskit/cmd/analyze_basis.cpp
     mpskit/cmd/entanglement_entropy.cpp
     mpskit/cmd/list_observables.cpp
     mpskit/cmd/list_one_point.cpp

diff --git a/mpskit/cmd/analyze_basis.cpp b/mpskit/cmd/analyze_basis.cpp
@@ -0,0  1,77 @@
 #include "analyze_basis.hpp"
 
 #include <cmath>
 #include <iostream>
 
 #include <highfive/H5DataSet.hpp>
 #include <highfive/H5DataSpace.hpp>
 #include <highfive/H5File.hpp>
 #include <itensor/mps/mps.h>
 #include <itensor/mps/sites/spinhalf.h>
 #include <itensor/util/readwrite.h>
 
 #include "../json.hpp"
 #include "../models/model.hpp"
 #include "../models/registry.hpp"
 
 int cmdAnalyzeBasis(const std::string &input_path, const std::string &psi_path, const std::string &output_path)
 {
     auto input = loadJSON(input_path);
     auto model = createModel1D(input["model"]);
     auto sites = model->getSites();
 
     // read MPS
     auto psi = itensor::readFromFile<itensor::MPS>(psi_path);
 
     // auto sites = itensor::SiteSet(itensor::siteInds(psi));
     const auto num_sites = static_cast<std::size_t>(sites.length());
     const auto local_dim = static_cast<std::size_t>(sites(1).size());
     const std::size_t num_states = 1ul << num_sites;
 
     if (local_dim != 2ul)
     {
         std::cerr << "Currently only implement for local_dim == 2, got local_dim == " << local_dim << '\n';
         return 1;
     }
 
     if (num_sites > 24ul)
     {
         std::cerr << "Refusing to project onto more than 2^24 states.\n";
         return 1;
     }
 
     try
     {
         HighFive::File file(output_path,
                             HighFive::File::Overwrite | HighFive::File::Create | HighFive::File::ReadWrite);
         HighFive::DataSet dset_states = file.createDataSet<int>(
             "states", HighFive::DataSpace({static_cast<std::size_t>(num_states), static_cast<std::size_t>(num_sites)}));
         HighFive::DataSet dset_overlaps =
             file.createDataSet<double>("overlap", HighFive::DataSpace({static_cast<std::size_t>(num_states)}));
 
         itensor::InitState init_state(sites, "Dn");
         std::vector<std::size_t> configuration(num_sites, 0ul);
 
         for (std::size_t index = 0; index < num_states;   index)
         {
             for (std::size_t i = 0; i < num_sites;   i)
             {
                 bool bit = (index >> i) & 1ul;
                 configuration[i] = bit ? 1ul : 0ul;
                 init_state.set(static_cast<int>(i   1), bit ? "Up" : "Dn");
             }
 
             const auto overlap = itensor::innerC(psi, itensor::MPS(init_state));
             const auto overlap_abs = std::abs(overlap);
 
             dset_states.select({index, 0}, {1, num_sites}).write(configuration);
             dset_overlaps.select({index}).write(overlap_abs * overlap_abs);
         }
     }
     catch (HighFive::Exception &e)
     {
         std::cerr << e.what() << '\n';
     }
 
     return 0;
 }
diff --git a/mpskit/cmd/analyze_basis.hpp b/mpskit/cmd/analyze_basis.hpp
@@ -0,0  1,8 @@
 #ifndef MPSKIT_CMD_ANALYZE_BASIS
 #define MPSKIT_CMD_ANALYZE_BASIS
 
 #include <string>
 
 int cmdAnalyzeBasis(const std::string &input_path, const std::string &psi_path, const std::string &output_path);
 
 #endif /* MPSKIT_CMD_ANALYZE_BASIS */
diff --git a/mpskit/models/spin_half/2d/xy_spin_glass_square.cpp b/mpskit/models/spin_half/2d/xy_spin_glass_square.cpp
@@ -0,0  1,5 @@
 #include "xy_spin_glass_square.hpp"
 
 XYSpinGlassSquare::XYSpinGlassSquare(const json& js)
 : SpinHalfSquare(js["Lx"].get<int>(), js["Ly"].get<int>(<))
 {}
diff --git a/mpskit/models/spin_half/2d/xy_spin_glass_square.hpp b/mpskit/models/spin_half/2d/xy_spin_glass_square.hpp
@@ -0,0  1,20 @@
 #ifndef MPSKIT_MODELS_SPIN_HALF_2D_XY_SPIN_GLASS_SQUARE
 #define MPSKIT_MODELS_SPIN_HALF_2D_XY_SPIN_GLASS_SQUARE
 
 #include "../../../json.hpp"
 #include "spin_half_square.hpp"
 
 class XYSpinGlassSquare : public SpinHalfSquare
 {
   protected:
     Real m_alpha;
 
   public:
     XYSpinGlassSquare(const json &js);
 
     const Real &getAlpha() const;
 
     virtual void print(std::ostream &stream) const override;
 };
 
 #endif /* MPSKIT_MODELS_SPIN_HALF_2D_XY_SPIN_GLASS_SQUARE */