In this chapter, the Josephson diode effect (JDE or \(\Delta I_{c}\) ) is studied in a material which combines the properties of topological states and reduced dimensionality offered by van der Waals materials. NiTe2 is a van der Waals material and a type-II Dirac semimetal with the Dirac cone close to the Fermi level, as evidenced from ARPES studies [94,95]. It also has a surface state with a Rashba spin-momentum locking and a large spin-splitting of 120 \( {me}V \) close to the Fermi energy. Since NiTe2 has these surface states right at the Fermi energy, the spin–orbit coupling emerging from these states are expected to dominate its electrical transport characteristics. We study the effects of this spin-orbit coupling arising from the topological surface states (TSS) in the superconducting phase by fabricating lateral Josephson junctions of NiTe2. The very low resistance of NiTe2 and its high stability under ambient conditions make it suitable to fabricate lateral Josephson junctions without much preclusions. We observe a JDE in the presence of an in-plane magnetic field. JDE in this system is quantified and found to have an antisymmetric dependence on the magnitude and direction of the applied magnetic field. We attribute the existence of this effect in this system to the Cooper pairs from the helical surface states acquiring a non-zero pair momentum in the presence of a magnetic field, as opposed to zero momentum Cooper pairs in a conventional BCS superconductor. This phenomenon is called as finite momentum Cooper pairing (FMCP) [7, 8, 33]. We use a simple Ginzburg-Landau analysis to describe the Josephson junction with broken inversion and time-reversal symmetries to show the existence of asymmetric critical currents and their dependence on temperature and applied magnetic fields. We confirm that this simple model captures all the experimental features of our observed JDE. We also perform independent studies verifying the existence of finite momentum Cooper pairing in the system by applying in-plane magnetic fields along the direction of current and quantify it by looking at the evolution of the Fraunhofer interference pattern [96, 97]. We find that the value of finite-momentum obtained from this measurement is of the same order of magnitude as the value of finite-momentum along the perpendicular direction, determined using the model used to calculate JDE. We suggest two possible microscopic mechanisms as the origin of finite-momentum Cooper pairing in the system in the presence of a magnetic field: 1) the existence of spin-momentum locked surface states with large Rashba spin splitting on the surface of NiTe2 as seen through ARPES and 2) the presence of screening currents on the niobium electrodes that generate finite momentum Cooper pairs. We estimate that the FMCP created due to screening currents is an order of magnitude lower than that created by the spin-orbit splitting in NiTe2.