Relationship between susceptibility and spin stiffness of mesoscopic quantum antiferromagnets

✍ Scribed by Scott Allen; Daniel Loss

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 311 KB
• Volume: 239
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/s0378-4371(97)00021-6

✦ Synopsis

We investigate the quantmn antiferromagnetic Heisenberg spin chain of integer spin S in the semiclassical limit (S >> 1) for a non-uniform system of finite-size and temperature. At low temperatures and in the mesoscopic regime with the correlation length being larger than the characteristic system size, boundary conditions significantly affect the scaling behavior of the spin stiffness ps and the magnetic response. Using a coherent spin-state path integral formulation and allowing for a non-uniform time varying external magnetic field we determine the dynamic susceptibility tensor if/3 We find that stiffness and susceptibility satisfy a remarkable relation in the mesoscopic regime, viz. ps/c2= Z ~. We briefly discuss the experimental consequences of this relationship.