About

Hello! I am Somesh Chandra Ganguli and I am currently working as a Research Fellow at the Atomic Scale Physics group in the Department of Applied Physics, Aalto University. You can check out my official research website here and my list of publications in my Google Scholar page.

Current research themes

Artificial Heavy fermion vdW heterostructure:

We have demonstrated for the first time that heavy fermionic behavior can be created artificially using vdW epitaxy, employing heterostructure of 2 different phases of the same material TaS2. Stacking 1H-TaS2 hosting 2-D conduction electrons, and 1T-TaS2 hosting localized magnetic moments gives rise to Kondo lattice and heavy-fermion hybridization.

Reference: Nature 599, 582 (2021)

Unconventional superconductivity in monolayer transition metal dichalcogenides:

I have demonstrated the presence of strong correlations by observing enhanced Coulomb repulsion at sizeable length scale, much larger than SC Coherence length in 1H-NbSe2.

I have also shown that 1H-TaS2 demonstrates superconductivity with many body fluctuations consistent with a nodal order parameter and is driven to a conventional s-wave superconductor upon inclusion of non-magnetic disorder.

References: Nano Lett. 22, 5, 1845 (2022)

Advanced Materials 35, 2305409 (2023).

Visualization of Moiré Magnons:

I have demonstrated by employing inelastic tunnelling spectroscopy (IETS) and Quasi-particle interference (QPI) imaging techniques, that the collective spin excitations in monolayer ferromagnet CrBr3 can be modulated by the Moiré pattern of the CrBr3 with substrate HOPG.

References: Nano Lett. 23, 8, 3412 (2023)

Artificial topological superconductivity:

We have demonstrated the existence of topological superconductivity and Majorana zero mode in the vdW heterostructure between ML ferromagnet CrBr3 and bulk superconductor NbSe2 as well as demonstrating the influence of Moiré pattern between CrBr3 and NbSe2 in the modulation of the topological gap as well as the Majorana zero mode.

References: Nature 588, 424 (2020)

Nano Lett. 22, 1, 328–333 (2022)

Adv. Mater. 33, 2006850 (2021)

volume

588,

pages

424–428 (2020)

Past research themes

Order-disorder transition of vortex lattice:

During my Ph.D, I have demonstrated disorder induced 2-step melting of vortex lattice in Co-intercalated bulk NbSe2 by successive destruction of positional and orientational order . Furthermore, I have explored the nature of these two steps of melting by superheating and supercooling measurements as well as the effect of crystalline lattice on the melting process.

References: Scientific Reports 5, 10613 (2015)

Phys. Rev. B 93, 144503 (2016)

J. Phys.: Condens. Matter 28 165701 (2016)

EPL, 123, 20004 (2018)

Emergence of nanoscale inhomogeneity in the superconducting state of a homogeneously disordered conventional superconductor :

We have demonstrated using scanning tunneling spectroscopy and high resolution scanning transmission electron microscopy, that under the competing effects of strong homogeneous disorder and superconducting correlations in disordered NbN thin films, the emergence of an inhomogeneous superconducting state, consisting of domains made of phase coherent and incoherent Cooper pairs.

References: Scientific Reports 3, 2979 (2013)

Phys. Rev. B 87, 184509 (2013)

Andreev bound state and multiple energy gaps in the noncentrosymmetric superconductor BiPd:

We have demonstrated using directional point contact Andreev reflection measurements on high-quality single crystals of the noncentrosymmetric superconductor BiPd, the presence of multiple superconducting energy gaps providing strong evidence for the presence of an unconventional order parameter in this material. .

References: Phys. Rev. B 86, 094520 (2012)

A 350 mK, 9 T scanning tunneling microscope for the study of superconducting thin films on insulating substrates and single crystals

We constructed a home-built low temperature, high field scanning tunneling microscope (STM) operating down to 350 mK and in magnetic fields up to 9 T, with thin film deposition and in situ single crystal cleaving capabilities. The design of STM head and sample holder allowed us to get spectroscopic data on superconducting thin films grown in situ on insulating substrates.

References: Review of Scientific Instruments 84, 123905 (2013).