Publications
Recent results
Phase biasing a Josephson Junction away from the ground state
By building a Josephson nano-junction directly onto a Rashba interface (Pt/Cu) we demonstrated that signatures of interfacial spin moment can be directly detected via the Josephson effect. In this case, a quasiparticle current at the Pt/Cu interface of a planar Nb-(Pt/Cu)-Nb Josephson junction resulted in a Rashba-Edelstein spin density. In the presence of a perpendicular magnetic field, the flux due to this spin density tightly coupled to the flux quantum and caused a shift in the Fraunhofer pattern of these devices. In these devices we also showed that it is possible to lock a desirable zero-field phase using field sweep history.
- Shown above is a conceptual schematic of the device showing the various relevant processes in the current carrying condition above and below the Tc of Nb. The composite image also shows the relative shift in the Fraunhofer patterns of a JJ and a SQUID in presence of a Pt underlayer, compared to the case without any Platinum underlayer.
More information @ Tapas Senapati et al., Nature Communications 14, 7415 (2023)
Superconducting shell on ferromagnetic Ni nanoparticle
Superconducting NiBi3 grows naturally on Ni films when a layer of Bi is evaporated on Ni, as verified by several groups including ours. This happens by a process of reaction diffusion, where the rate of the formation of a chemical end product dynamically varies with not only the amount of reactants but also on the amount of end product at any particular time. In collaboration with the group of Dr Pratap Sahoo, we have shown that the reactive self diffusion process at Ni-Bi interface can be utilized to obtain superconductor (NiBi3) coated ferromagnetic (Ni) nanoparticles by an entirely physical process. Such hybrid nano-particles are useful for studies of S-F proximity effect in confined geometries.
-Shown above is the process we followed to obtain the S-F nanoparticles. A TEM image shows the NiBi3 boundary of a sinle Ni nanoparticle.
More information @ Laxmipriya Nanda et al., J. Nanopart. Res. 25, 251 (2023)
Crystalline superconducting NiBi3 Nanowires made by PVD
We fabricated (in collaboration with the group of Dr Pratap Sahoo) single crystal superconducting NiBi3 nanorods in a fully physical route. This was possible due to the unique combination of materials, viz. Ni and Bi which self diffuse to form superconducting NiBi3. Co-evaporation of Ni and Bi at temperatures close to the melting temperature of Bismuth led to activated formation of NiBi3 nanorod via a process very similar to the famous VLS growth mechanism of semiconducting nanowires. The amorphous Bi cap at the top of the NiBi3 nanorods testifies for this fact.
- Shown above is a composite image with a single nanorod of NiBi3, a cartoon of the growth mechanism and a high resolution transmission electron micrograph of the tip of the nanorod.
More information @ Laxmipriya Nanda et al., Journal of Alloys and Compounds 960, 170948 (2023)
Full list of publications from the lab
2023
Fabrication of Ni-NiBi3 ferromagnet-superconductor nano particles.
Laxmipriya Nanda, Subhashree Sahoo, Pratap K Sahoo, & kartik Senapati, Journal of Nanoparticle Research 25, 251 (2023).
Phase biasing of a Josephson junction using Rashba–Edelstein effect.
Tapas Senapati, Ashwin Kumar Karnad, & Kartik Senapati, Nature Communications 14, 7415 (2023).
Optimization of the superconducting properties of NbTiN thin films by variation of the N2 partial pressure during sputter deposition.
Pratiksha Pratap, Laxmipriya Nanda, Kartik Senapati, R. P. Aloysius, and Venugopal Achanta, Supercond. Sci. and Technol. 36, 085017 (2023)
Bismuth Phase Dependent Growth of Superconducting NiBi3 Nanorods.
Laxmipriya Nanda, Bidyadhar Das, Subhashree Sahoo, Pratap K. Sahoo, and Kartik Senapati, Journal of Alloys and Compounds 960, 170948 (2023)
Emergent quantum transport due to quenched magnetic impurity scattering by antiferromagnetic proximity in SrCuO2/SrIrO3
S. Jana, T Senapati, SG Bhat, SN Sarangi, K Senapati, and D Samal, Phys. Rev. B 107, 134415 (2023).
Multiband character revealed from weak antilocalization in platinum thin films.
Subhadip Jana, T. Senapati, K. Senapati, and D. Samal, Phys. Rev. B 107, 035127 (2023).
Reaction-Diffusion-Driven Stoichiometric Gradient in Coevaporated Superconducting NiBi3 Thin Films.
Bidyadhar Das, Tapas Ranjan Senapati, Ashok Kumar Yadav, GR Umapathy, Sambhu Nath Jha, Kartik Senapati, Pratap Kumar Sahoo, Cryst. Growth Des. 23, 980–988 (2023)
2022
Aspects of long range spin–triplet correlations in superconductor/ferromagnet hetero-structures.
Ekta Bhatia and Kartik Senapati, Superconductor Science and Technology 35 (9), 094004 (2022).
Phase evolution in thermally annealed Ni/Bi multilayers studied by X-ray absorption spectroscopy.
Bidyadhar Das, Madhusmita Sahoo, Abhilash Patra, Ashok K Yadav, SN Jha, Prasanjit Samal, Kartik Senapati, Pratap K Sahoo, Phys. Chem. Chem. Phys. 24, 4415 (2022)
2021
Unconventional domain wall magnetoresistance of patterned Ni/Nb bilayer structures below superconducting transition temperature of Nb.
E Bhatia, Zainab Hussain, VR Reddy, ZH Barber, K Senapati, Journal of Physics: Condensed Matter 33, 295803 (2021)
Nanoscale Domain Wall Engineered Spin-Triplet Josephson Junctions and SQUID.
E Bhatia, A Srivastava, J Devine-Stoneman, NA Stelmashenko, ZH Barber, J. W. A. Robinson, and Kartik Senapati, Nano Letters 21, 3092 (2021).
Study of magnetization reversal in Néel and Bloch regime of nickel and permalloy stripes using Kerr microscopy.
E Bhatia, Z Hussain, VR Reddy, K Senapati, Physica B: Condensed Matter 609, 412877 (2021).
2020
Tuning field-emission characteristics of ZnO nanorods through defect engineering via O+ ion irradiation.
A Singh, K Senapati, R Singh, P Rajput, T Som, PK Sahoo, Journal of Applied Physics 128 , 054304 (2020)
Magnetic field tunable superconducting transition in Nb/Co/Py/Nb exchange spring multilayers.
Ekta Bhatia, J. M. Devine-Stoneman, Zoe H. Barber, J. W. A. Robinson, and Kartik Senapati, Appl. Phys. Lett. 116, 112601(2020).
2019
Domain wall induced modulation of low field HT phase diagram in patterned superconductor- ferromagnet stripes.
Ekta Bhatia, Zoe H Barber, Ilari J Maasilta, and Kartik Senapati, AIP Advances 9 (4), 045107 (2019)
2018
Superconductivity, Kondo effect, and observation of self-organized pattern formation in inter-
metallic NiBi3 thin films.
Ekta Bhatia, A. Talapatra, J. R. Mohanty, K. Senapati, Intermetallics 94, 160-164 (2018)
A study of electron and thermal transport in layered titanium disulphide single crystals.
D. Suri, V. Siva, S. Joshi, K. Senapati, P.K. Sahoo, S. Varma, R.S. Patel, Journal of Physics: Condensed Matter 29 (48), 485708 (2018) .
2017
Role of work function in field emission enhancement of Au island decorated vertically aligned ZnO nanotapers.
Avanendra Singh, Kartik Senapati, Mohit Kumar, T. Som, A. Sinha, and Pratap K Sahoo, Applied Surface Science, 411, 117-123 (2017)
Progressive magnetic softening of ferromagnetic layers in multilayer ferromagnet-nonmagnet systems and the role of granularity.
Siddharth S. Sahu, Vantari Siva, Paresh C. Pradhan, Maheswar Nayak, Kartik Senapati, and Pratap K. Sahoo, Journal of Applied Physics 121, 213905 (2017)
Suppression of near band edge emission in specially engineered ZnO twin nanorods.
A. Singh, K. Senapati, B. Satpati, P.K. Sahoo, Phys. Chem. Chem. Phys. 19, 14012 (2017)
2016
Unusual ferromagnetic behaviour of embedded non-functionalized Au nanoparticles in Bi/Au bilayer films.
S. Prusty, V. Siva, N. Shukla, B. Satpati, K. Senapati, P.K. Sahoo, RSC Advances 6 (108), 106584 (2016)
Superconducting proximity effect in NiBi3-Ni-NiBi3 trilayer system with sharp superconductor-ferromagnet boundaries.
V. Siva, P.C. Pradhan, G.S. Babu, M. Nayak, P.K. Sahoo, K. Senapati, Journal of Applied Physics 119, 063902 (2016)
Ion irradiation induced phase transition of Co in Co/Au multilayers.
V. Siva, S.S. Sahu, D.P. Datta, P.C. Pradhan, M. Nayak, V. Solanki, D. Topwal, K. Senapati, P. K. Sahoo, Journal of Alloys and Compounds 680, 722-728 (2016)
2015
Spontaneous formation of superconducting NiBi3 phase in Ni-Bi bilayer films.
V.Siva, K.Senapati, B.Satpati, S.Prusty, D.K.Avasthi, D.Kanjilal, P.K.Sahoo, Journal of Applied Physics 117, 083902 (2015)
Nanoscale interface engineering in ZnO twin nanorods for proposed phonon tunnel devices.
A. Singh, K. Senapati, B. Satpati, M. Kumar, P.K. Sahoo, Phys. Chem. Chem. Phys. 17 , 4277-4282 (2015)
2013
Electric Field Dependent Spin Polarization in GdN Spin Filter Tunnel Junctions.
A. Pal, K. Senapati, Z. H. Barber, M. G. Blamire, Advanced Materials 25 (39), 5581-5585 (2013)
Suppression of magnetic coupling in superconducting GdN-NbN-GdN trilayers.
K. Senapati, M. G. Blamire, Z. H. Barber, Applied Physics Letters 103, 132406 (2013)