① Research on charge-spin related materials and devices
A typical device is the magnetic tunnel junction. In our laboratory, we research materials to dramatically improve the characteristics (tunnel magnetoresistance effect). A magnetic tunnel junction is a laminated element in which an insulating thin film is sandwiched between conductive thin films that have magnetic properties. Each layer is on the order of a few nanometers thick. When a voltage is applied to the conductors above and below the insulator, a current flows due to the quantum mechanical tunneling effect. It is also called a TMR element because it exhibits a tunnel magnetoresistive effect (TMR effect) in which the electrical resistance of the element changes depending on whether the magnetization (orientation of the magnetic poles) of the two upper and lower magnets is parallel or antiparallel. This element has been used in magnetic sensors and hard disk magnetic heads. Recently, memory companies around the world are developing magnetoresistive random access memory (MRAM). In addition, basic research on various artificial intelligence hardware using this is being advanced worldwide. The tunnel magnetoresistive effect is the most fundamental characteristic that determines the performance of these various applied products.
Our laboratory pursues new and original magnetic electrode materials and element insulation barrier materials led by PI Mizukami, and also conducts unique research and development that incorporates computational science, information science, and machine learning in collaboration with other groups.
This research is supported by CREST (JST) and Grant-in-Aid for Scientific Research (S) (JSPS).
JST CREST : Overview and Results (Mizukami)
JSPSKAKENHI (S) : Overview and Results (Mizukami)
② Research on light-spin related materials and devices
We are conducting research to control the state and motion of magnetism (spin) in nanomagnetic materials using laser light. We are also researching basic physics and materials for high efficiency. It has been known for a long time that there are various waves woven by magnetism (spin) in magnetic materials. Research on low-power, high-speed von Neumann computers and non-Von Neumann computers that use spin waves and spin states as carriers for information storage, processing, and transmission is underway worldwide. This is because the energy required for the motion of the spin is very small, so there is the possibility of creating a new computer with high energy efficiency.
In our laboratory, we have constructed an original spin measurement technique using laser light led by PI Mizukami, and are proceeding with unique research using pump-probe microscopes and terahertz wave radiation. We are also researching memories and interfaces using light-spin and their materials. In addition, under the leadership of Assistant Professor Iihama, we are conducting research on computers using light-spin waves.
③ Research on quantum-spin related materials and devices
Research and development of various quantum technologies are progressing worldwide. Research and development of quantum technology using spin defects in diamond is one of them.
In our laboratory, we are researching on new technology comprising both classic and quantum physiscs/materials, in particular spin defects in Diamond.