[en] We investigate experimentally and theoretically the superconducting properties of an Al thin film covering a periodic array of Co/Pt magnetic disks with out-of-plane magnetization for different radii of the magnetic disks and constant period of the magnetic lattice. The presence of the arrays of magnetic dots leads to a quantized displacement of the normal/superconducting phase boundary along the magnetic field axis, with each step corresponding to a flux-quantum per unit cell of the magnetic lattice. We demonstrate that this so-called field-induced superconductivity is strongly dependent not only on the chosen magnetic material and its magnetization M but also on the radius R of the constructed magnetic disks. Since field-induced superconductivity is directly linked to the nucleation of vortex-antivortex (V-AV) pairs, a theoretical M-R equilibrium phase boundary is presented, delimiting regions of different numbers of induced V-AV pairs per magnet. A good qualitative and quantitative agreement is found between theory and experiment.
A. I. Buzdin, Rev. Mod. Phys. RMPHAT 0034-6861 10.1103/RevModPhys.77.935 77, 935 (2005).
I. F. Lyuksyutov and V. L. Pokrovsky, Adv. Phys. ADPHAH 0001-8732 54, 67 (2005).
A. I. Buzdin and A. S. Mel'nikov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.67.020503 67, 020503 (R) (2003);
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).
A. Yu. Aladyshkin and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.74.064503 74, 064503 (2006).
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).
Yu. I. Bespyatykh and W. Wasilevski, Phys. Solid State PSOSED 1063-7834 10.1134/1.1349464 43, 224 (2001).
C. Bell, S. Turşucu, and J. Aarts, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.74.214520 74, 214520 (2006).
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).
M. V. Milošević and F. M. Peeters, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.68.024509 68, 024509 (2003).
D. J. Priour, Jr. and H. A. Fertig, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.93.057003 93, 057003 (2004).
M. V. Milošević and F. M. Peeters, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.93.267006 93, 267006 (2004).
M. V. Milošević and F. M. Peeters, Europhys. Lett. EULEEJ 0295-5075 10.1209/epl/i2005-10032-4 70, 670 (2005).
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).
W. Gillijns, A. V. Silhanek, and V. V. Moshchalkov, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.74.220509 74, 220509 (R) (2006).
W. B. Zeper, F. J. A. M. Greidanus, P. F. Carcia, and C. R. Fincher, J. Appl. Phys. JAPIAU 0021-8979 10.1063/1.343189 65, 4971 (1989).
D. J. Morgan and J. B. Ketterson, Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.80.3614 80, 3614 (1998).
M. Lange, M. J. Van Bael, and V. V. Moshchalkov, J. Magn. Magn. Mater. JMMMDC 0304-8853 10.1016/S0304-8853(01)00861-7 240, 595 (2002).
A. V. Silhanek, W. Gillijns, M. V. Milošević, A. Volodin, V. V. Moshchalkov, and F. M. Peeters, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.76.100502 76, 100502 (R) (2007).
M. M. Doria, J. E. Gubernatis, and D. Rainer, Phys. Rev. B PRBMDO 0163-1829 10.1103/PhysRevB.39.9573 39, 9573 (1989).
