| The development of semiconductor devices is limited by the high power consumption and further physical dimension reduction. Spintronic devices, especially the magnetic tunnel junction (MTJ) based devices, have advantages of non-volatility, reconfigurable capability, fast-switching speed, small-dimension, and compatibility to semiconductor devices, which is a promising candidate for future logic and memory devices. However, the previously proposed MTJ logic devices have been operated independently and therefore are limited to only basic logic operations. Consequently, the MTJ device has only been used as ancillary device in the circuit, rather than the main computation component.;In this thesis, study has been done on both spintronic logic and memory devices. In the first part, systematic study has been performed on MTJ based logic devices in order to expand the functionalities and properties of MTJ devices. Basic logic cell with three-input has been designed and simulated. Nano-magnetic-channel has been proposed, which is the first design to realize the communication between the MTJ logic cells. With basic logic unit as a building block, a spintronic logic circuit has been designed with MTJ as the dominant component. HSPICE simulation has been done for this spintronic logic circuit, which acts as an Arithmetic Logic Unit.;In the spintronic memory device part, study has been focused on the fundamental study on the current induced switching in MTJ devices with hybrid free layer. With hybrid free layer, magnetic non-uniformity is introduced along the current direction, which induces extra spin torque component. Unique current-induced switching has been observed and studied in the hybrid free layer MTJ. Adiabatic spin torque, which is introduced by spatial non-uniform magnetization in the hybrid free layer, plays an important role for the unique switching. By tuning the bias field, single-polar current switching was achieved in this hybrid MTJ device, which gives the potential application of unidirectional switching in the spintronic memory devices. |
