Spin-charge fluctuations in itinerant helical magnets

✍ Scribed by Wolfram Brenig

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 696 KB
• Volume: 508
• Category: Article
• ISSN: 0003-3804
• DOI: 10.1002/andp.2065080202

✦ Synopsis

Using a generalized random phase approach quantum fluctuations beyond the helical mean-field states of the Hubbard model off half filling are discussed. The collective mode spectrum is shown to exhibit spin-charge mixing and is found to be strongly renormalized by coupling to low-energy incoherent particle-hole excitations. Results for the collective mode dispersion whlch displays a significant anisotropy are presented for selected helical phases. Moreover phase space regions of 'missing' modes are identified with a finite wave length instability of the helical states suggesting novel inhomogeneous phases of the doped Hubbard model.