[en] The competition between two regimes of the nucleation of superconductivity is investigated experimentally and theoretically in a mesoscopic disk-shaped superconductor/ferromagnet hybrid. By changing the magnetic state of a multilayered Co/Pt disk one can reversibly affect the magnetic-field dependence of the critical temperature T(c)(H) of an Al layer. We demonstrate that an enhancement of the magnetic field near the edge of the out-of-plane magnetized disk either stimulates the nucleation of superconductivity at the disk perimeter due to the field compensation effect or prevents it due to edge magnetic barrier (for relatively low parallel to H parallel to values). As a consequence, the presence of such magnetic-field pattern makes it possible to eliminate boundary effects for mesoscopic superconducting samples. Switching from one nucleation regime to another while sweeping H leads to an abrupt change of the slope of the T(c)(H) envelope.
J. Flouquet and A. Buzdin, Phys. World PHWOEW 0953-8585 15 (1), 41 (2002)
I. F. Lyuksyutov and V. L. Pokrovsky, Adv. Phys. 54, 67 (2004) 0001-8732
A. I. Buzdin, Rev. Mod. Phys. RMPHAT 0034-6861 10.1103/RevModPhys.77.935 77, 935 (2005).
Y. Otani, B. Pannetier, J. P. Nozières, and D. Givord, J. Magn. Magn. Mater. JMMMDC 0304-8853 10.1016/0304-8853(93)90705-7 126, 622 (1993)
A. Yu. Aladyshkin, A. I. Buzdin, A. A. Fraerman, A. S. Mel'nikov, D. A. Ryzhov, and A. V. Sokolov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.68. 184508 68, 184508 (2003)
M. Lange, M. J. Van Bael, Y. Bruynseraede, and V. V. Moshchalkov, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.90.197006 90, 197006 (2003)
Z. Yang, M. Lange, A. Volodin, R. Szymczak, and V. V. Moshchalkov, Nat. Mater. NMAACR 1476-1122 10.1038/nmat1222 3, 793 (2004)
W. Gillijns, A. Yu. Aladyshkin, M. Lange, M. J. Van Bael, and V. V. Moshchalkov, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.95.227003 95, 227003 (2005)
M. V. Milošević and F. M. Peeters, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.94.227001 94, 227001 (2005).
L. F. Chibotaru, A. Ceulemans, M. Morelle, G. Teniers, C. Carballeira, and V. V. Moshchalkov, J. Math. Phys. JMAPAQ 0022-2488 10.1063/1.2013107 46, 095108 (2005).
C. Carballeira, V. V. Moshchalkov, L. F. Chibotaru, and A. Ceulemans, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.95.237003 95, 237003 (2005).
A. Yu. Aladyshkin, D. A. Ryzhov, A. V. Samokhvalov, D. A. Savinov, A. S. Mel'nikov, and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.75.184519 75, 184519 (2007).
A. Yu. Aladyshkin, A. S. Mel'nikov, and D. A. Ryzhov, J. Phys.: Condens. Matter JCOMEL 0953-8984 10.1088/0953-8984/15/38/024 15, 6591 (2003).
W. Gillijns, A. V. Silhanek, and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.74.220509 74, 220509 (R) (2006).
A. Yu. Aladyshkin and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.74.064503 74, 064503 (2006).
W. Gillijns, A. Yu. Aladyshkin, A. V. Silhanek, and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.76.060503 76, 060503 (R) (2007).
See, e.g., M. Tinkham, Introduction to Superconductivity (McGraw-Hill, New York, 1996), Chap..
H. J. Fink and A. G. Presson, Phys. Rev. PHRVAO 0031-899X 10.1103/PhysRev.151.219 151, 219 (1966)
V. V. Moshchalkov, L. Gielen, C. Strunk, R. Jonckheere, X. Qiu, C. Van Haesendonck, and Y. Bruynseraede, Nature (London) NATUAS 0028-0836 10.1038/373319a0 373, 319 (1995)
A. K. Geim, I. V. Grigorieva, S. V. Dubonos, J. G. S. Lok, J. C. Maan, A. E. Filippov, and F. M. Peeters, Nature (London) NATUAS 0028-0836 10.1038/36797 390, 259 (1997)
V. A. Schweigert and F. M. Peeters, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.57.13817 57, 13817 (1998)
H. T. Jadallah, J. Rubinstein, and P. Sternberg, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.82.2935 82, 2935 (1999)
L. F. Chibotaru, A. Ceulemans, V. Bruyndoncx, and V. V. Moshchalkov, Nature (London) NATUAS 0028-0836 10.1038/35048521 408, 833 (2000).
W. A. Little and R. D. Parks, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.9.9 9, 9 (1962).
L. D. Landau and E. M. Lifshitz, Electrodynamics of Continuum Media, 2nd ed. (Pergamon, Oxford, 1984).
Handbook of Mathematical Functions, Natl. Bur. Stand. Appl. Math. Ser. No. 55, edited by, M. Abramowitz, and, I. A. Stegun, (U.S. GPO, Washington, DC, 1965).