def test_tocoo(): syst = kwant.Builder() lat1 = kwant.lattice.chain(norbs=1) syst[lat1(0)] = syst[lat1(1)] = 0 syst = syst.finalized() op = ops.Density(syst) assert isinstance(op.tocoo(), coo_matrix) # Constant and non-constant values. assert np.all(op.tocoo().todense() == np.eye(2)) op = ops.Density(syst, lambda site: 1) assert np.all(op.tocoo().todense() == np.eye(2)) # Correct treatment of where op = ops.Density(syst, where=[lat1(0)]) assert np.all(op.tocoo().todense() == [[1, 0], [0, 0]]) # No accidental transpose. syst = kwant.Builder() lat2 = kwant.lattice.chain(norbs=2) syst[lat2(0)] = lambda site, paramerer: np.eye(2) syst = syst.finalized() op = ops.Density(syst, [[1, 1], [0, 1]], check_hermiticity=False) assert np.all(op.tocoo().todense() == [[1, 1], [0, 1]]) op = ops.Density(syst, lambda site, p: [[1, 1], [0, 1]], check_hermiticity=False) op = op.bind(args=(1, )) raises(ValueError, op.tocoo, [1])
def test_opservables_finite(): lat, syst = _random_square_system(3) fsyst = syst.finalized() ev, wfs = la.eigh(fsyst.hamiltonian_submatrix()) Q = ops.Density(fsyst) Qtot = ops.Density(fsyst, sum=True) J = ops.Current(fsyst) K = ops.Source(fsyst) for i, wf in enumerate(wfs.T): # wfs[:, i] is i'th eigenvector assert np.allclose(Q.act(wf), wf) # this operation is identity _test(Q, wf, reduced_val=1) # eigenvectors are normalized _test(Qtot, wf, per_el_val=1) # eigenvectors are normalized _test(J, wf, per_el_val=0) # time-reversal symmetry: no current _test(K, wf, per_el_val=0) # onsite commutes with hamiltonian # check that we get correct (complex) output for bra, ket in zip(wfs.T, wfs.T): _test(Q, bra, ket, per_el_val=(bra * ket)) # check with get_hermiticity=False Qi = ops.Density(fsyst, 1j, check_hermiticity=False) for wf in wfs.T: # wfs[:, i] is i'th eigenvector assert np.allclose(Qi.act(wf), 1j * wf) # test with different numbers of orbitals lat2 = kwant.lattice.chain(norbs=2) extra_sites = [lat2(i) for i in range(len(fsyst.sites))] syst[extra_sites] = np.eye(2) syst[zip(fsyst.sites, extra_sites)] = ta.matrix([1, 1]) fsyst = syst.finalized() ev, wfs = la.eigh(fsyst.hamiltonian_submatrix()) Q = ops.Density(fsyst) Qtot = ops.Density(fsyst, sum=True) J = ops.Current(fsyst) K = ops.Source(fsyst) for wf in wfs.T: # wfs[:, i] is i'th eigenvector assert np.allclose(Q.act(wf), wf) # this operation is identity _test(Q, wf, reduced_val=1) # eigenvectors are normalized _test(Qtot, wf, per_el_val=1) # eigenvectors are normalized _test(J, wf, per_el_val=0) # time-reversal symmetry: no current _test(K, wf, per_el_val=0) # onsite commutes with hamiltonian
def test_operator_construction(): lat, syst = _random_square_system(3) fsyst = syst.finalized() N = len(fsyst.sites) # test construction failure if norbs not given latnone = kwant.lattice.chain() syst[latnone(0)] = 1 for A in opservables: raises(ValueError, A, syst.finalized()) del syst[latnone(0)] # test construction failure when dimensions of onsite do not match for A in opservables: raises(ValueError, A, fsyst, onsite=np.eye(2)) # test that error is raised when input array is the wrong size for A in opservables: a = A(fsyst) kets = list(map(np.ones, [(0, ), (N - 1, ), (N + 1, ), (N, 1)])) for ket in kets: raises(ValueError, a, ket) raises(ValueError, a, ket, ket) raises(ValueError, a.act, ket) raises(ValueError, a.act, ket, ket) # Test failure on non-hermitian for A in (ops.Density, ops.Current, ops.Source): raises(ValueError, A, fsyst, 1j) # Test output dtype ket = np.ones(len(fsyst.sites)) for A in (ops.Density, ops.Current, ops.Source): a = A(fsyst) a_nonherm = A(fsyst, check_hermiticity=False) assert a(ket, ket).dtype == np.complex128 assert a(ket).dtype == np.float64 assert a_nonherm(ket, ket).dtype == np.complex128 assert a_nonherm(ket).dtype == np.complex128 # test construction with different numbers of orbitals lat2 = kwant.lattice.chain(norbs=2) extra_sites = [lat2(i) for i in range(N)] syst[extra_sites] = np.eye(2) syst[zip(fsyst.sites, extra_sites)] = ta.matrix([1, 1]) for A in opservables: raises(ValueError, A, syst.finalized(), onsite=np.eye(2)) A(syst.finalized()) A.onsite == np.eye(2) del syst[extra_sites] check = [(ops.Density, np.arange(N).reshape(-1, 1), ta.identity(1)), (ops.Current, np.array(list(fsyst.graph)), ta.identity(1)), (ops.Source, np.arange(N).reshape(-1, 1), ta.identity(1))] # test basic construction for A, where, onsite in check: a = A(fsyst) assert np.all(np.asarray(a.where) == where) assert all(a.onsite == onsite for i in range(N)) # test construction with dict `onsite` for A in opservables: B = A(fsyst, {lat: 1}) assert all(B.onsite(i) == 1 for i in range(N)) # test construction with a functional onsite for A in opservables: B = A(fsyst, lambda site: site.pos[0]) # x-position operator assert all(B.onsite(i) == fsyst.sites[i].pos[0] for i in range(N)) # test construction with `where` given by a sequence where = [lat(2, 2), lat(1, 1)] fwhere = tuple(fsyst.id_by_site[s] for s in where) A = ops.Density(fsyst, where=where) assert np.all(np.asarray(A.where).reshape(-1) == fwhere) where = [(lat(2, 2), lat(1, 2)), (lat(0, 0), lat(0, 1))] fwhere = np.asarray([(fsyst.id_by_site[a], fsyst.id_by_site[b]) for a, b in where]) A = ops.Current(fsyst, where=where) assert np.all(np.asarray(A.where) == fwhere) # test construction with `where` given by a function tag_list = [(1, 0), (1, 1), (1, 2)] def where(site): return site.tag in tag_list A = ops.Density(fsyst, where=where) assert all(fsyst.sites[A.where[w, 0]].tag in tag_list for w in range(A.where.shape[0])) where_list = set(kwant.HoppingKind((1, 0), lat)(syst)) fwhere_list = set( (fsyst.id_by_site[a], fsyst.id_by_site[b]) for a, b in where_list) def where(a, b): return (a, b) in where_list A = ops.Current(fsyst, where=where) assert all((a, b) in fwhere_list for a, b in A.where) # test that `sum` is passed to constructors correctly for A in opservables: A(fsyst, sum=True).sum == True