Coupling coefficient distribution in the doorway mechanism
(2010) In New Journal of Physics 12. Abstract
 In manybody and other systems, the physics situation often allows one to interpret certain, distinct states by means of a simple picture. In this interpretation, the distinct states are not eigenstates of the full Hamiltonian. Hence, there is an interaction that makes the distinct states act as doorways into background states which are modeled statistically. The crucial quantities are the overlaps between the eigenstates of the full Hamiltonian and the doorway states, that is, the coupling coefficients occurring in the expansion of true eigenstates in the simple model basis. Recently, the distribution of the maximum coupling coefficients was introduced as a new, highly sensitive statistical observable. In the particularly important regime... (More)
 In manybody and other systems, the physics situation often allows one to interpret certain, distinct states by means of a simple picture. In this interpretation, the distinct states are not eigenstates of the full Hamiltonian. Hence, there is an interaction that makes the distinct states act as doorways into background states which are modeled statistically. The crucial quantities are the overlaps between the eigenstates of the full Hamiltonian and the doorway states, that is, the coupling coefficients occurring in the expansion of true eigenstates in the simple model basis. Recently, the distribution of the maximum coupling coefficients was introduced as a new, highly sensitive statistical observable. In the particularly important regime of weak interactions, this distribution is very well approximated by the fidelity distribution, defined as the distribution of the overlap between the doorway states with interaction and without interaction. Using a random matrix model, we calculate the latter distribution exactly for regular and chaotic background states in the cases of preserved and fully broken timereversal invariance. We also perform numerical simulations and find excellent agreement with our analytical results. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/1673009
 author
 Kohler, Heiner; Guhr, Thomas and Åberg, Sven ^{LU}
 organization
 publishing date
 2010
 type
 Contribution to journal
 publication status
 published
 subject
 in
 New Journal of Physics
 volume
 12
 publisher
 IOP Publishing Ltd.
 external identifiers

 wos:000281232700005
 scopus:77955392810
 ISSN
 13672630
 DOI
 10.1088/13672630/12/7/073026
 language
 English
 LU publication?
 yes
 id
 0da9ca493b85464dbf6bcd0687fa265b (old id 1673009)
 date added to LUP
 20100923 12:24:05
 date last changed
 20180318 04:01:30
@article{0da9ca493b85464dbf6bcd0687fa265b, abstract = {In manybody and other systems, the physics situation often allows one to interpret certain, distinct states by means of a simple picture. In this interpretation, the distinct states are not eigenstates of the full Hamiltonian. Hence, there is an interaction that makes the distinct states act as doorways into background states which are modeled statistically. The crucial quantities are the overlaps between the eigenstates of the full Hamiltonian and the doorway states, that is, the coupling coefficients occurring in the expansion of true eigenstates in the simple model basis. Recently, the distribution of the maximum coupling coefficients was introduced as a new, highly sensitive statistical observable. In the particularly important regime of weak interactions, this distribution is very well approximated by the fidelity distribution, defined as the distribution of the overlap between the doorway states with interaction and without interaction. Using a random matrix model, we calculate the latter distribution exactly for regular and chaotic background states in the cases of preserved and fully broken timereversal invariance. We also perform numerical simulations and find excellent agreement with our analytical results.}, articleno = {073026}, author = {Kohler, Heiner and Guhr, Thomas and Åberg, Sven}, issn = {13672630}, language = {eng}, publisher = {IOP Publishing Ltd.}, series = {New Journal of Physics}, title = {Coupling coefficient distribution in the doorway mechanism}, url = {http://dx.doi.org/10.1088/13672630/12/7/073026}, volume = {12}, year = {2010}, }