The mobility of the PBS films is found to be two orders of magnitude smaller than reported for bulk crystals. In this work, we report the first growth and characterization of Pd 3Bi 2S 2 (PBS) thin films using pulse laser deposition technique (PLD) and magneto-transport properties of PBS films prepared under different post annealing conditions. WAL is observed in topological materials, as an important consequence of spin momentum locking, resulting in a relative π Berry phase acquired by electrons executing time-reversed paths 27, 28. These effects can be experimentally verified using electron transport such as magneto-resistance (MR), Hall effect, etc. The constructive or destructive interference of electrons moving through time reversed paths gives rise to negative or positive correction to conductivity, which is known as weak localization or anti-localization (WL/WAL) 22– 25. Additionally, reduction of system dimensionality from three dimensional (3D) to two dimensional (2D), is expected to lead to the emergence of several quantum phenomena at low temperatures, including weak localization (WL) or weak anti-localization (WAL), quantum interference (QI) 22– 25, and universal conductance fluctuations (UCF) 26. To reveal contributions of the topological surface states it is essential to reduce the mobility of the bulk charge carriers. The magneto-transport study on single-crystal indeed revealed interesting features like a large non-saturating magneto-resistance, which was ascribed to the high mobility of the charge carriers 21. In previous studies, the magneto-transport has been reported on polycrystalline, single-crystalline, and nanoparticle samples of Pd 3Bi 2S 2 19– 21. Pd 3Bi 2S 2 with space group 199 is one such material proposed to host exotic fermions having three-fold degenerate band crossing just 0.1 eV away from the Fermi level 18. et al have theoretically predicted the existence of exotic fermions (beyond Dirac, Weyl, Majorana) having three, six, and eightfold degenerate band crossing in various materials 18. Recently, based on certain space group symmetries, Bradlyn. The topological semimetals exhibit unusual phenomena such as extremely large magneto-resistance, chiral anomaly induced negative MR, high mobility, and anomalous Hall effect 14– 17. Among the TSM candidates, Cd 3As 2 and Na 3Bi were first theoretically predicted and experimentally verified to host Dirac fermions 7– 10, whereas Weyl fermion were identified in the T X ( T = Ta, Nb X = As, P) family of materials 11– 13. The quasiparticles in Weyl and Dirac semimetals have two and four-fold degeneracy. On breaking either TRS or IS, this Dirac node splits into two Weyl nodes with opposite chiral charge, forming a Weyl semimetal 5. In a Dirac semimetal, conduction and valence band touch each other linearly at discrete points in the Brillouin zone called Dirac nodes which are protected by time-reversal symmetry (TRS) and Inversion symmetry (IS) 5, 6. Topological semimetals (TSM) can be classified into Dirac semimetals and Weyl semimetals 3– 5. Topological Insulators (TI) have a bulk band gap with conducting edge or surface states protected by time-reversal symmetry (TRS) 1, 2. have sparked worldwide interest owing to their novel physical properties and potential applications in the field of spintronics 1– 5. Topological materials such as topological insulators, topological semimetals, etc.
0 kommentar(er)
