Tapan Kumar Das, PhD

Postdoctoral research

fellow @ Weizmann Institute

of Science, Rehovot, Israel

Email: tapiphysics@gmail.com

Google scholar

Orcid

Research Interest:

Developing new phenomenon and study the spin selective mechanism in chiral molecules using spin-Hall, spin valve, spin-transistor and electrochemical spin-chemistry.
Study the lasing action and whispering gallery modes coupling in semiconductor QDs.
Halide perovskites and semiconductor QDs for energy applications.
Exploring the potential application of chiral molecules and bio-derived electronics.

Recent Work Highlights

1. Insights into the Mechanism of Chiral‐Induced Spin Selectivity: The Effect of Magnetic Field Direction and Temperature (Advanced Materials )

Highlights

Magnetoresistance is measured as a function of the angle between the magnetization of the ferromagnet and the surface normal. The angular distribution obtained only if the monolayer has significant effective spin orbit coupling (SOC), that includes contribution from the electron–phonon interactions and dissipation.

Das et al., Advanced Materials 2024, 36, 2313708

2. Spin Polarized Current in Chiral Organic Radical Monolayers (Journal of Material Chemistry A)

Highlights

In this context, we conducted a study to explore the spin filtering capabilities of a monolayer of thia-bridged triarylamine hetero[4]helicene radical cation chemisorbed on a metallic surface. Magnetic-conductive atomic force microscopy revealed efficient electron spin filtering at exceptionally low potentials.

Giaconi et al., Journal of Material Chemistry A. 12, 10029-10035, 2024

3. The role of electrons’ spin in DNA oxidative damage recognition (Cell Reports Physical Science )

Highlights

DNA is oxidatively damaged at different locations The enzyme-DNA recognition process involves charge and electrons’ spin polarization The importance of the electrons’

Zhu et al., Cell Reports Physical Science 3, 101157

Spin-induced asymmetry reaction-The formation of asymmetric carbon by electropolymerization (Science Advances)

Highlights

The process of forming a chiral polymer from an achiral reagent without a chiral catalyst demonstrates the power of spin-induced enantiospecific chemistry.

Bhowmick et al., Sci. Adv. 8, eabq2727 (2022)

Mutual monomer orientation to bias the supramolecular polymerization of [6] Helicenes and the resulting circularly polarized light and spin filtering properties (Journal of the American Chemical Society )

Highlights

We report on the synthesis and self-assembly of 2,15- and 4,13-disubstituted carbo[6]helicenes 1 and 2 bearing 3,4,5-tridodecyloxybenzamide groups. These helical supramolecular structures with high chiroptical activity, when deposited on conductive surfaces, revealed highly efficient electron-spin filtering abilities, with electron spin polarizations up to 80% for 1 and 60% for 2, as measured by magnetic conducting atomic force microscopy.

Temperature-Dependent Chiral-Induced Spin Selectivity Effect: Experiments and Theory (J. Phys. Chem. C )

Highlights

The theoretical explanation for the chiral-induced spin selectivity effect, in which electrons’ passage through a chiral system depends on their spin and the handedness of the system, remains incomplete. Although most experimental work was performed at room temperature, most of the proposed theories did not include vibrations. Here, we present temperature-dependent experiments and a theoretical model that captures all observations and provides spin polarization values that are consistent with the experimental results.

Metal Organic Spin Transistor (Nano Letters)

We developed a spin transistor using these crystals and based on the chiral-induced spin selectivity effect. This device features a memristor type behavior, which depend on trapping both charges and spins. The spin properties are monitored by Hall signal and by an external magnetic field. The spin transistor exhibits nonlinear drain-source currents, with multilevel controlled states generated by the magnetization of the source. Varying the source magnetization enables a six-level readout for the two-terminal device.