Onset of a Two-Dimensional Superconducting Phase in a Topological-Insulator-Normal-Metal Bi_{1-x}Sb_{x}/Pt Junction Fabricated by Ion-Beam Techniques.

Inducing superconductivity in a topological insulator can lead to novel quantum effects. However, experimental approaches to turn a topological insulator into a superconductor are limited. Here, we report on superconductivity in topological insulator Bi_{0.91}Sb_{0.09} induced via focused ion-beam deposition of a Pt thin film. The superconducting phase exhibits a Berezinski-Kosterlitz-Thouless transition, demonstrative of its two-dimensional character. From the in-plane upper critical field measurements, we estimate the superconducting thickness to be ∼17  nm for a 5.5-μm-thick sample. Our results provide evidence that the interface superconductivity could originate from the surface states of Bi_{0.91}Sb_{0.09}.

[1]  W. Kwok,et al.  Robust odd-parity superconductivity in the doped topological insulator Nb x Bi 2 Se 3 , 2017, 1704.01225.

[2]  Jian Wang,et al.  On the origin of critical temperature enhancement in atomically thin superconductors , 2017, 1703.09850.

[3]  Anna Keselman,et al.  Topological Superconductivity in a Planar Josephson Junction , 2016, 1609.09482.

[4]  G. Gu,et al.  Superconductivity with two-fold symmetry in topological superconductor SrxBi2Se3 , 2016, Science China Physics, Mechanics & Astronomy.

[5]  Y. Hor,et al.  Rotational Symmetry Breaking in a Trigonal superconductor Nb-doped Bi$_{2}$Se$_{3}$ , 2016, 1603.04040.

[6]  E. Talantsev,et al.  Universal self-field critical current for thin-film superconductors , 2015, Nature Communications.

[7]  K. T. Law,et al.  Ising pairing in superconducting NbSe2 atomic layers , 2015, Nature Physics.

[8]  P. Kim,et al.  Nature of the quantum metal in a two-dimensional crystalline superconductor , 2015, Nature Physics.

[9]  Shruti,et al.  Superconductivity by Sr Intercalation in Layered Topological Insulator Bi2Se3 , 2015, 1505.05394.

[10]  L. Pi,et al.  Superconductivity with Topological Surface State in SrxBi₂Se₃. , 2015, Journal of the American Chemical Society.

[11]  Xiong-Jun Liu,et al.  Observation of superconductivity induced by a point contact on 3D Dirac semimetal Cd3As2 crystals. , 2015, Nature materials.

[12]  Su-Yang Xu,et al.  Momentum-space imaging of Cooper pairing in a half-Dirac-gas topological superconductor , 2014, Nature Physics.

[13]  A. Ganguli,et al.  Unconventional superconductivity at mesoscopic point contacts on the 3D Dirac semimetal Cd3As2. , 2014, Nature materials.

[14]  T. Schäpers,et al.  Crossover from Josephson effect to single interface Andreev reflection in asymmetric superconductor/nanowire junctions. , 2014, Nano letters.

[15]  Rosa Córdoba Castillo.  Functional Nanostructures Fabricated by Focused Electron/Ion Beam Induced Deposition , 2013 .

[16]  D. Qu,et al.  Observation of huge surface hole mobility in the topological insulator Bi(0.91)Sb(0.09) (111). , 2013, Physical review letters.

[17]  K. T. Law,et al.  Two-dimensional superconductivity at the interface of a Bi2Te3/FeTe heterostructure , 2013, Nature Communications.

[18]  R. Masutomi,et al.  Two-dimensional superconducting state of monolayer Pb films grown on GaAs(110) in a strong parallel magnetic field. , 2013, Physical review letters.

[19]  D. Goldhaber-Gordon,et al.  Unconventional Josephson effect in hybrid superconductor-topological insulator devices. , 2012, Physical review letters.

[20]  W. G. van der Wiel,et al.  Josephson supercurrent through a topological insulator surface state. , 2011, Nature materials.

[21]  P. Goldbart,et al.  Approaching zero-temperature metallic states in mesoscopic superconductor–normal–superconductor arrays , 2011, Nature Physics.

[22]  H. Hwang,et al.  Intrinsic spin-orbit coupling in superconducting delta-doped SrTiO3 heterostructures , 2011, 1106.5193.

[23]  Z. Wang,et al.  Superconducting transitions of intrinsic arrays of weakly coupled one-dimensional superconducting chains: the case of the extreme quasi-1D superconductor Tl2Mo6Se6 , 2011, 1106.2405.

[24]  N. P. Ong,et al.  Quantum Oscillations and Hall Anomaly of Surface States in the Topological Insulator Bi2Te3 , 2010, Science.

[25]  X. Qi,et al.  Topological insulators and superconductors , 2010, 1008.2026.

[26]  P. Sheng,et al.  Superconducting resistive transition in coupled arrays of 4 Å carbon nanotubes , 2010 .

[27]  T. Mallouk,et al.  Interplay between superconductivity and ferromagnetism in crystalline nanowires , 2010 .

[28]  C. Kane,et al.  Topological Insulators , 2019, Electromagnetic Anisotropy and Bianisotropy.

[29]  Masatoshi Sato,et al.  Topological odd-parity superconductors , 2009, 0912.5281.

[30]  A. Williams,et al.  Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator. , 2009, Physical review letters.

[31]  G. Koren,et al.  Enhancement of the superconducting transition temperature of La2-xSrxCuO4 bilayers: role of pairing and phase stiffness. , 2008, Physical review letters.

[32]  D. Hsieh,et al.  A topological Dirac insulator in a quantum spin Hall phase , 2008, Nature.

[33]  Shinsei Ryu,et al.  Classification of topological insulators and superconductors in three spatial dimensions , 2008, 0803.2786.

[34]  N. Reyren,et al.  Superconducting Interfaces Between Insulating Oxides , 2007, Science.

[35]  L. Fu,et al.  Superconducting proximity effect and majorana fermions at the surface of a topological insulator. , 2007, Physical review letters.

[36]  Y. Matsuda,et al.  Fulde–Ferrell–Larkin–Ovchinnikov State in Heavy Fermion Superconductors , 2007, cond-mat/0702481.

[37]  Liang Fu,et al.  Topological insulators with inversion symmetry , 2006, cond-mat/0611341.

[38]  C. Kane,et al.  Z2 topological order and the quantum spin Hall effect. , 2005, Physical review letters.

[39]  T. Klapwijk,et al.  Resistance of superconducting nanowires connected to normal-metal leads , 2004, cond-mat/0401364.

[40]  L. Gor’kov,et al.  Inhomogeneous stripe phase revisited for surface superconductivity. , 2002, Physical review letters.

[41]  L. Gor’kov,et al.  Superconducting 2D system with lifted spin degeneracy: mixed singlet-triplet state. , 2001, Physical review letters.

[42]  D. Mailly,et al.  Detection of doubled shot noise in short normal-metal/ superconductor junctions , 2000, Nature.

[43]  G. Borghs,et al.  Superconductors coupled with a two-dimensional electron gas in GaAs/AlGaAs and InAs/AlGaSb heterostructures , 1994 .

[44]  Jansen,et al.  Superconductivity in Bi observed with point contacts. , 1986, Physical review. B, Condensed matter.

[45]  A. Hebard,et al.  Critical-exponent measurements of a two-dimensional superconductor , 1983 .

[46]  J. C. Garland,et al.  Kosterlitz-Thouless Transition in Proximity-Coupled Superconducting Arrays , 1981 .

[47]  David R. Nelson,et al.  Resistive transition in superconducting films , 1979 .

[48]  J. E. Mooij,et al.  Possibility of Vortex-Antivortex Pair Dissociation in Two-Dimensional Superconductors , 1979 .

[49]  D. Thouless,et al.  Ordering, metastability and phase transitions in two-dimensional systems , 1973 .

[50]  B. McCombe,et al.  Magnetothermal Oscillations and Spin Splitting in Bismuth and Antimony , 1967 .

[51]  L. Esaki,et al.  New Phenomenon in Semimetals and Semiconductors , 1965 .

[52]  Vinay Ambegaokar,et al.  Tunneling between superconductors , 1963 .

[53]  Clogston.  Upper limit for the critical field in hard superconductors. [V/sub 2. 95/Ga, NbâSn,VâSi, V/sub 1. 95/ Ga] , 1962 .

[54]  B. Chandrasekhar.  A NOTE ON THE MAXIMUM CRITICAL FIELD OF HIGH‐FIELD SUPERCONDUCTORS , 1962 .

[55]  H. Alloul.  Introduction to Superconductivity , 2011 .

[56]  L. Gor’kov,et al.  Superconducting 2D System with Lifted Spin Degeneracy , 2001 .