changed sign of J interaction in the FeAs model. (65607fb7) · Commits · NDIP / Tool Sources / Direct-Geometry Spectroscopy / DCA / DCA Main

include/dca/phys/domains/cluster/symmetries/symmetry_operations/2d/Cn_2d.hpp

+1 −1

Original line number	Diff line number	Diff line
		1;// Copyright (C) 2018 ETH Zurich
		;// Copyright (C) 2018 ETH Zurich
		// Copyright (C) 2018 UT-Battelle, LLC
		// All rights reserved.
		//

include/dca/phys/models/analytic_hamiltonians/fe_as_lattice.hpp

+51 −63

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@

		#include "dca/function/domains.hpp"
		#include "dca/function/function.hpp"
		#include "dca/phys/domains/cluster/symmetries/point_groups/2d/2d_square.hpp"
		#include "dca/phys/models/analytic_hamiltonians/bilayer_lattice.hpp"
		#include "dca/phys/models/analytic_hamiltonians/cluster_shape_type.hpp"

		@@ -56,9 +57,6 @@ public:
		static void initializeNonDensityInteraction(
		func::function<double, func::dmn_variadic<Nu, Nu, Nu, Nu, RDmn>>& non_density_interaction,
		const parameters_type& parameters);

		static int transformationSignofK(int b1, int b2, int s);
		static int transformationSignofR(int b1, int b2, int s);
		};

		template <typename PointGroupType>
		@@ -72,7 +70,6 @@ void FeAsLattice<PointGroupType>::initialize_H_0(
		if (SpinDmn::dmn_size() != 2)
		throw std::logic_error("Spin domain size must be 2.");

		const auto& k_vecs = KDmn::get_elements();
		const auto t1 = parameters.get_t1();
		const auto t2 = parameters.get_t2();
		const auto t3 = parameters.get_t3();
		@@ -98,13 +95,13 @@ void FeAsLattice<PointGroupType>::initialize_H_0(
		H_0(1, s, 0, s, k_ind) = val_01;
		}
		}
		}

		template <typename PointGroupType>
		template <typename BandDmn, typename SpinDmn, typename RDmn, typename parameters_type>
		void FeAsLattice<PointGroupType>::initialize_H_interaction(
		func::function<double, func::dmn_variadic<func::dmn_variadic<BandDmn, SpinDmn>,
		func::dmn_variadic<BandDmn, SpinDmn>, RDmn>> &
		H_interaction,
		func::dmn_variadic<BandDmn, SpinDmn>, RDmn>>& H_interaction,
		const parameters_type& parameters) {
		if (BandDmn::dmn_size() != BANDS)
		throw std::logic_error("Bilayer lattice has two bands.");
		@@ -121,13 +118,13 @@ void FeAsLattice<PointGroupType>::initialize_H_0(
		for (int b2 = 0; b2 < BANDS; ++b2)
		for (int s1 = 0; s1 < 2; ++s1)
		for (int s2 = 0; s2 < 2; s2++) {
		// Coulomb repulsion and contribution from S*S interaction.
		// Coulomb repulsion and contribution from -J S_z*S_z interaction.
		if (b1 == b2 and s1 != s2)
		H_interaction(b1, s1, b2, s2, origin) = U;
		else if (b1 != b2 and s1 == s2)
		H_interaction(b1, s1, b2, s2, origin) = V + J;
		else if (b1 != b2 and s1 != s2)
		H_interaction(b1, s1, b2, s2, origin) = V - J;
		else if (b1 != b2 and s1 != s2)
		H_interaction(b1, s1, b2, s2, origin) = V + J;
		}
		}

		@@ -145,23 +142,14 @@ void FeAsLattice<PointGroupType>::initialize_H_0(
		for (int b2 = 0; b2 < BANDS; b2++) {
		if (b1 == b2)
		continue;
		// spin-flip interaction equivalent to S^+S^- and S^-S^+ interactions.
		non_density_interaction(nu(b1, up), nu(b2, up), nu(b2, down), nu(b1, down), 0) = -J;
		// spin-flip interaction coming from the -J * S_b1^+S_b2^- Hamiltonian term.
		// Note: a factor of -1 comes from rearranging the fermion operators.
		non_density_interaction(nu(b1, up), nu(b2, up), nu(b2, down), nu(b1, down), 0) = J;
		}
		}

		template <typename PointGroupType>
		int FeAsLattice<PointGroupType>::transformationSignofR(int b1, int b2, int s) {
		return 1;
		}

		template <typename PointGroupType>
		int FeAsLattice<PointGroupType>::transformationSignofK(int b1, int b2, int s) {
		return 1;
		}

		} // namespace models
		} // namespace models
		} // namespace phys
		} // namespace dca

		#endif // DCA_PHYS_MODELS_ANALYTIC_HAMILTONIANS_FE_AS_LATTICE_HPP

include/dca/phys/parameters/model_parameters_fe_as.inc

+4 −4

Original line number	Diff line number	Diff line
		@@ -32,16 +32,16 @@ public:
		// t3: next-nearest-neighbour, same orbital.
		// t4: next-nearest-neighbour, opposite orbital.
		double get_t1() const {
		return std::array<double, 4>{t1_, t2_, t3_, t4_};
		return t1_;
		}
		double get_t2() const {
		return std::array<double, 4>{t1_, t2_, t3_, t4_};
		return t2_;
		}
		double get_t3() const {
		return std::array<double, 4>{t1_, t2_, t3_, t4_};
		return t3_;
		}
		double get_t4() const {
		return std::array<double, 4>{t1_, t2_, t3_, t4_};
		return t4_;
		}

		// On-site, same orbital repulsion.