Abstract
Since 1997 we systematically perform direct angle resolved photoemission spectroscopy (ARPES) on in-situ grown thin (<30 nm) cuprate films. Specifically, we probe low-energy electronic structure and properties of high-T c superconductors (HTSC) under different degrees of epitaxial (compressive vs. tensile) strain. In overdoped and underdoped in-plane compressed (the strain is induced by the choice of substrate) ≈15 nm thin La2 − x Sr x CuO4 (LSCO) films we almost double T c to 40 K, from 20 K and 24 K, respectively. Yet the Fermi surface (FS) remains essentially two-dimensional. In contrast, ARPES data under tensile strain exhibit the dispersion that is three-dimensional, yet T c drastically decreases. It seems that the in-plane compressive strain tends to push the apical oxygen far away from the CuO2 plane, enhances the two-dimensional character of the dispersion and increases T c, while the tensile strain acts in the opposite direction and the resulting dispersion is three-dimensional. We have established the shape of the FS for both cases, and all our data are consistent with other ongoing studies, like EXAFS. As the actual lattice of cuprates is like a ‘Napoleon-cake’, i.e. rigid CuO2 planes alternating with softer ‘reservoir’, that distort differently under strain, our data rule out all oversimplified two-dimensional (rigid lattice) mean field models. The work is still in progress on optimized La-doped Bi-2201 films with enhanced T c.
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References
M Cyrot and D Pavuna, Introduction to superconductivity and high-T c materials (World Scientific, 1992), the new edition is currently being prepared See also J Bok, G Deutscher, D Pavuna, S A Wolf (eds), The gap symmetry and fluctuations in high-Tc superconductors (NATO B371, Kluwer-Plenum, 1998)
D W Lynch and C G Olsen, Photoemission studies on high temperature superconductors (Cambridge Univ. Press, 1999) ISBN 0 521 55189
J C Campuzano et al, CM0209476
Karl Alex Mueller, personal communications (2006) In contrast, see P W Anderson, Nature Phys. 2, 626 (2006) or the whole issue Nature Phys. — 20 years of HTSC (March 2006)
G Baskaran, personal communication, Kanpur (2006), also CM9910161v1
T Timusk and B Statt, Rep. Prog. Phys. 62(1), 61 (1999)
G Deutscher, Nature (London) 397, 410 (1999)
B Batlogg and C Varma, Phys. World 13(2), 33 (2000) and references therein
H Sato and M Naito, Physica C274, 221 (1997)
J P Locquet et al, Nature (London) 394, 453 (1998)
I Bozovic et al, Phys. Rev. Lett. 89(10), 107001-1 (2002)
G N Angilella et al, cond-mat/0201509 (2002) and references therein
As an example of controversies in the ARPES studies of HTSC cuprates, see the respective web pages of Z X Shen, http://arpes.stanford.edu/; J Fink et al, http://www.ifw-dresden.de/iff/11/arpes/preprints_new.htm
For an update of electron doped cuprates, see http://www.csr.umd.edu/csrpage/research/superconductingmat/cuprates.htm
I Bozovic, D Pavuna (eds), Oxide superconductor physics and nano-engineering, vol. I–VI (SPIE — Int. Society for Opt. Eng., Bellingham, USA, 1994, 1996, 1998, 2000, 2002, 2005
I Vobornik, H Berger, D Pavuna, G Margaritondo, F Rullier-Albenque, L Forro and M Grioni, Phys. Rev. Lett. 82, 3128 (1999)
D Pavuna, I Vobornik and G Margaritondo, J. Supercond. 13, 749 (2000)
G Margaritondo, M Grioni, I Vobornik and D Pavuna, Physica C364, 1 (2001)
M Abrecht, D Ariosa, D Cloetta, D Pavuna, L Perfetti, M Grioni and G Margaritondo, Int. J. Mod. Phys. B17, 3449 (2003)
M Abrecht, D Ariosa, D Cloetta, G Margaritondo and D Pavuna, SPIE 4811, 102, Bellingham (2002); Curr. Appl. Phys. 2(4), 345 (2002); J. Phys. D33, 234 (2000); Physica C365, 538 (2001)
M Abrecht et al, Phys. Rev. Lett. 91, 057002 (2003); See also comment reply in Phys. Rev. Lett. 92, 129702 (2004) More details are given in Mike Abrecht, Photoemission studies of thin films grown by pulsed laser deposition; epitaxial strain effects on the electronic structure of high temperature superconductors; EPFL Thesis no. 2792 (2003); download page: http://library.epfl.ch/en/theses/?nr=2792&lang=fre
D Cloetta, D Ariosa, C Cancellieri, M Abrecht, S Mitrovic and D Pavuna, Phys. Rev. B74, 014519 (2006)
D Cloetta, D Ariosa, M Abrecht, C Cancellieri, S Mitrovic, M Papagno and D Pavuna, SPIE 5932 (2005)
Dominique Cloetta, Properties of La 2−x Sr x CuO 4 under epitaxial strain: Photoemission on ultra thin films grown by pulsed laser deposition, EPFL Thesis no. 3333 (2005), download page: http://library.epfl.ch/en/theses/?nr=3333&lang=fre
A Bansil et al, Phys. Rev. B71, 012503 (2005) and references therein
See the publications by Karl Alex Mueller, or by J C Phillips and many authors associated with the web-page: http://www.superstripes.com
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Pavuna, D., Ariosa, D., Cloetta, D. et al. Direct angle resolved photoemission spectroscopy and superconductivity of strained high-T c films. Pramana - J Phys 70, 237–243 (2008). https://doi.org/10.1007/s12043-008-0042-z
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DOI: https://doi.org/10.1007/s12043-008-0042-z
Keywords
- Condensed matter physics
- high-T c superconductivity
- electronic properties
- photoemission spectroscopy
- angle resolved photoemission spectroscopy
- cuprates
- films
- strain
- pulsed laser deposition