Impurity Energy Level Within The Haldane Gap

An impurity bond $J{'}$ in a periodic 1D antiferromagnetic, spin 1 chain with exchange $J$ is considered. Using the numerical density matrix renormalization group method, we find an impurity energy level in the Haldane gap, corresponding to a bound state near the impurity bond. When $J{'}<J$ the level changes gradually from the edge of the Haldane gap to the ground state energy as the deviation $dev=(J-J{'})/J$ changes from 0 to 1. It seems that there is no threshold. Yet, there is a threshold when $J{'}>J$. The impurity level appears only when the deviation $dev=(J{'}-J)/J{'}$ is greater than $B_{c}$, which is near 0.3 in our calculation.Comment: Latex file,9 pages uuencoded compressed postscript including 4 figure

J=0, J=J_{max} and quadrupole pairing

We consider 2 neutrons and 2 protons in the g_{9/2} shell.Wave functions and energy levels are obtained for various interactions. The wave functions for states with total angular momentum I greater or equal to 10 are not affected by what the pairing interacton (J=0 T=1) is.Other parts of the interaction are therefore of increased importance

Volume 51, Number 2

Volume 51, Number 2. 6 pages including covers and advertisements. Miller, Sam The American Inferno Magner, Tom Canonized McNiel, Paul Nightshade\u27s Obbligato Rybarski, Michael McNeil, Paul Stew Ellis, J. Patrick Egan, Gerard Today Is Rain McNeil, Neil C. hope & consolation 1971 McNeil, Paul Outer Flight O\u27Neil, Charles J. Jr. Freedom O\u27Neil, Charles J. Jr. More or Less O\u27Neil, Charles J. Jr. As a Seed O\u27Neil, Charles J. Jr. Confectioner O\u27Neil, Charles J. Jr. For Existential Mariners Egan, Gerard Thursday Night Bortolot, Gary Balder Osborne, J.C. The Death of the American Achilles Bortolot, Gary Childhood\u27s Dream Piergrossi, Joe Egan, Gerard Rover, Dominic, O.P. THREE POEMS Ellis, J. Patrick Peter and The Aberration Ellis, J. Patrick Media #7 Nadeau, Larry A GOOD PASTIME Ellis, J. Patrick Secondary Reader VOL. 5 Egan, Gerard Downtown Yet Not Spring Piergrossi, Joe I Knew A Little Midget Man Egan, Gerard Rhys, Skyles Red Worm Kilgallen, Michael Quarter Hour Valentine McNeil, Paul 1969 Political O\u27Neil, Charles J. Jr. To Go Piergrossi, Jo