Evidence of Critical Tunnelling Width in Ensuring Spin Polarized Asymmetric Negative Differential Resistance Feature in Two‐Dimensional g‐C₄N₃‐graphene‐g‐C₄N₃

Abstract

We report herein existence of a critical tunnelling width beyond which graphitic tunnelling nanostructures exhibit asymmetric spin polarized negative differential resistance feature. Our theoretical foray quite clearly establishes that even with a simple two-dimensional tunnelling nanostructure created by an assembly of ferromagnetic graphitic carbon nitride (g-C4N3) electrodes separated by insulating graphene sheet of variable lengths, there exists a critical tunnelling width at which the system switches from symmetric to asymmetric negative differential resistance feature. Presence of robust spin filer efficiency (100 %) over a wide range of bias variation (À 1.0 to + 1.0 V) added with negative differential resistance action makes the device with shorter tunnelling width of 22.36 Å and 31. 96 Å potentially useful as multifunctional spintronic device. However, at the critical tunnelling width of 36.69 Å and beyond the forward bias negative differential resistance features completely switches off and same is observed only in reverse bias. This switching action certainly opens up the prospect of logic gates operation in quantum circuits. Results obtained has been explained through transmission spectra, transmission pathways and molecular projected self-consistent Hamiltonian states analysis. Emergence of asymmetric IÀ V curve beyond critical tunnelling width has been explained by examining differences in spin injection coefficients.

Role of dopants in tuning spintronic features of lithium doped g-C4N3@Lin =1 to 4

“…However, in this context graphitic carbon nitride (g-C4N3) is found to be an ideal material to study as it possesses both the characters of metal-free magnetism and half metallicity in spite of being free from any 3d transitional metal elements [12,13]. It is well known that generally 2p electronic systems exhibits non-magnetic character in bulk systems but in case of ultrathin two dimensional structure like g-C4N3 the 2p electrons behave in a very peculiar way to manifest magnetic behaviour associated with half metallicity; which certainly makes it useful as a probable spintronic material [14][15][16][17][18][19][20][21]. In this context, it is worth noting that electronic structure property of g-C4N3 could be suitably tuned in presence of metallic dopants like Li atom.…”