| Spintronics utilizes electron spin degree of freedom for novel information storage and processing beyond. The key components in spintronics include creating, manipulating and detecting spins in a spin transport channel. Single layer graphene has emerged as the leading candidate for spin transport materials due to experimentally observed high mobility, long spin lifetimes and long spin diffusion lengths at room temperature. A nonvolatile, reconfigurable universal magneto-logic gate has been proposed based on the excellent spin transport properties of graphene. Integration of these logic gates can operate at high speed and consume less power in parallel data processing applications. This thesis is trying to experimentally implement this magneto-logic gate using state-of-art lateral graphene spin valves. Firstly, current-based detection of spin transport in graphene was demonstrated in graphene spin valve. This is important because the logic output of magneto-logic gate is a current signal which depends on spin accumulation in graphene. Secondly, bias dependent spin injection in graphene was studied. Spin injection across MgO tunnel barrier was found to strongly depend on the injection bias. Thirdly, by utilizing the observed bias dependence, XOR logic operation was successfully demonstrated in graphene devices with three ferromagnetic electrodes. This provides an important step forwards towards fully demonstration of the proposed five terminal magneto-logic gate. Lastly, successful spin injection and transport in epitaxy large area graphene was achieved. This indicates that large area graphene can be potentially used for large devices integration. |
