Creator | Title | Description | Subject | Date | ||
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1 |
![]() | Mattis, Daniel C. | Application of tridiagonalization to the many-body problem | The problem of a single magnetic, Wolff-model impurity in an otherwise ideal metallic host is investigated using the nonperturbative Lanczos method. Convergence is very rapid. The many-body ground-state energy is investigated and comparisons are made with Tomonaga operator theory and other weak-coup... | Lattice; Electrons; Interaction; Ground-state energy; Tridiagonalization; Magnetic impurity; Nonmagnetic metals | 1983 |
2 |
![]() | Mattis, Daniel C. | Application of tridiagonalization to the many-body problem. II. Finite T | In a previous paper of the same title, we obtained the ground-state energy of a magnetic (Wolff-model) impurity in a nonmagnetic metal. In the present Brief Report, we calculate the impurity's contribution to the density of states and heat capacity of the metal at low temperatures. Here, the Lancz... | Ground-state energy; Tridiagonalization; Magnetic impurity; Nonmagnetic metals; Heat capacity | 1984-06 |
3 |
![]() | Mattis, Daniel C. | Exactly solvable model of a magnetic impurity | A slight modification of the "mixing" term in Anderson's model of a magnetic impurity produces an exactly solvable model. Results of some preliminary calculations are given, and upper and lower bounds on Anderson's model are obtained by means of the exact solutions. . | Magnetic impurity; Ground-state energy; Free energy | 1971-11 |
4 |
![]() | Mattis, Daniel C. | Ground state of the Kondo model | The single-impurity Kondo problem is investigated with the use of the nonperturbative Lanczos (tridiagonalization) method. We are able to obtain an explicit expression for the ground-state energy in terms of the Kondo coupling constant J. The method places no restrictions on the range of J. | Kondo model; Ground-state energy; Coupling constant | 1985-06 |
5 |
![]() | Mattis, Daniel C. | Ground-state energy of Heisenberg antiferromagnet for spins s=1/2 and s=1 in d=1 and 2 dimensions | A simple real-space renormalization method yields the ground-state energy of the Heisenberg antiferromagnet. We find the ground-state energy per spin for s=1/2 (-0.4438 in ID , -0.6723 in 2D ) and s = 1 (-1.388 in ID and -1.907 in 2D) to three-figure accuracy, using properties of relatively small o... | Ground-state energy; Heisenberg antiferromagnet; Long-range order | 1988-07 |
6 |
![]() | Mattis, Daniel C. | Mattis and Pan reply | After several independent calculations failed to confirm our published1 numbers on the ground-state energy of the s = 1/2 antiferromagnet in two dimensions, we checked our computer programs and found some deplorable errors introduced in proceeding from one dimension to two. | Ground-state energy; Antiferromagnets; Long-range order | 1988 |
7 |
![]() | Mattis, Daniel C. | Multicomponent polaron | By a slight modification of the Fröhlich Hamiltonian (the introduction of an internal quantum number) we reduce the polaron problem to the solution of a continued fraction, even at finite temperature. We analyze both the stationary states and the resonances (in one- and three-dimensional versions o... | Ground-state energy; Coupling constant; Fröhlich model; Finite temperature | 1991-10 |