2001/11/08 by Ersin Keçecioğlu, Ersin Kececioglu, Anupam Garg · 1 citation
Biochemistry, Genetics and Molecular Biology · Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #Electron Spin Resonance Studies #Magnetism in coordination complexes #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.88.237205
4 pages, revtex4 format, 3 embedded eps figures
arxiv created 2001/11/08 · openalex publication_date 2002/05/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Coherent state path integrals are shown in general to contain instantons with jumps at the boundaries, i.e., boundary points lying outside classical phase space. Inclusion of these instantons is shown to resolve the "missing quench paradox" in the magnetic molecule Fe8, i.e., the fact that the tunneling between the ground Zeeman states of this molecule is quenched at only four magnetic field values, instead of the ten that would be expected from the topological Berry phase between interfering instantons. An approximate formula is found for the location of the four remaining quenches.