Frano, A.; Blanco-Canosa, S.; Schierle, E.; Lu, Y.; Wu, M.; Bluschke, M.; Minola, M.; Christiani, G.; Habermeier, H.U.; Logvenov, G.; Wang, Y.; van Aken, P.A.; Benckiser, E.; Weschke, E.; Le Tacon, M.; Keimer, B.: Long-range charge-density-wave proximity effect at cuprate/manganate interfaces. Nature Materials 15 (2016), p. 831-835
10.1038/nmat4682
Open Access Version

Abstract:
The interplay between charge density waves (CDWs) and high-temperature superconductivity is currently under intense investigation1–10. Experimental research on this issue is dicult because CDW formation in bulk copper oxides is strongly influenced by random disorder11–13, and a long-range-ordered CDWstate in high magnetic fields14–16 is dicult to access with spectroscopic and diraction probes. Here we use resonant X-ray scattering in zero magnetic field to show that interfaces with the metallic ferromagnet La2=3Ca1=3MnO3 greatly enhance CDW formation in the optimally doped high-temperature superconductor YBa2Cu3O6C (  1), and that this eect persists over several tens of nanometres. The wavevector of the incommensurate CDW serves as an internal calibration standard of the charge carrier concentration, which allows us to rule out any significant influence of oxygen non-stoichiometry, and to attribute the observed phenomenon to a genuine electronic proximity eect. Long-range proximity eects induced by heterointerfaces thus oer a powerful method to stabilize the charge-density-wave state in the cuprates and, more generally, to manipulate the interplay between dierent collective phenomena in metal oxides.