Using a unique molecular beam epitaxy system, we synthesize atomically smooth HTS thin films, multilayers and superlattices.1 Such heterostructures enable novel experiments that probe the basic physics of HTS. For example, we have established that HTS and anti-ferromagnetic phases separate on Ångstrom scale, while the pseudo-gap state apparently mixes with HTS over an anomalously large length scale ("Giant Proximity Effect").2
In this talk, I will review our most recent experiments on such films and superlattices, including XRD, AFM, angle-resolved TOF-ISARS, transport measurements, high-resolution TEM, resonant X-ray scattering, low-energy muon spin resonance, ultrafast photo-induced RHEED, COBRA surface crystallography, and ultra-high magnetic field spectroscopy. The results include an unambiguous demonstration of strong coupling of in-plane charge excitations to out-of-plane lattice vibrations3, a discovery of interface HTS4, and evidence that HTS occurs in a single CuO2 plane.
1I. Bozovic et al., Phys. Rev. Lett. 89, 107001 (2002); P. Abbamonte et al., Science 297, 581 (2002).
2I. Bozovic et al., Nature 422, 873 (2003); Phys. Rev. Lett. 93, 157002 (2004)
3N. Gedik et al., Science 316, 425 (2007); Z. Radovic et al., Phys. Rev. B 77, 092508 (2008)
4A. Gozar et al., Nature 455, 782 (2008).
Host: Gabi Kotliar