应魏福林教授邀请，新加坡南洋理工大学数理系Lew Wen Siang 助理教授将于2013年9月6日来我校访问交流并作报告，欢迎各位老师参加。 

 

    报告时间：2013年9月6日（星期五）下午15:00

 

The quest for higher density, lower power, and faster response are the driving force for multi-billion dollar research in non-volatile memory devices. Flash semiconductor memory has been dominating amongst other non-volatile memory devices partly due to its excellent scaling capability. However, the progressive density increment of the flash memory has shown the sign of slowing down. While extensive development is still going on to bring up the flash density alternative memory technologies are being seriously considered. One potential candidate is magnetic memory, which exploits the spin property of electron instead of charge. Spin-based technology has its typical advantages such as non-volatility, high endurance, fast switching and low operation energy. The most widely used magnetic memory of today is the hard disk drive but such device requires mechanical movement for read-write operation hence limiting its portability. A solid-state magnetic memory would be desirable if this is to be considered as a replacement of the flash memory. A few of such magnetic solid state memory devices are being extensively developed, namely MRAM and STT-RAM, which use arrays of field- or current-controlled magnetoresistive sensor as data storage media.  A newer approach is to exploit the movement of magnetic bit boundary or the domain wall along a magnetic nanowire element. In this talk, we specifically present our new approach in designing the domain-wall memory, where a bi-nanowire structure is used for memory storage. The unique feature is that the domain-wall movement is remotely driven hence the data storage element is free from electrical current.

Conventional logic gate structure is composed of a network circuit of multi CMOS transistor and each logical gate has its unique circuit. A simpler case is the combination of multi NAND gates for performing most logical functions. An entirely new concept is reconfigurable logic, where one universal structure is used to perform all logical gates function with the ease of a selector control. The research of the spintronic logic has been extensive and reconfigurable spintronic logic is a new challenge that, if materialized, will expand the spintronics application boundary from memory to logical calculation in the computation technology. We will present the design of such reconfigurable magnetic logic.

 

Dr. Lew is a full-time academic staff (Assistant Professor) at the School of Physical and Mathematical Sciences (Physics Division), Nanyang Technological University, Singapore. He received his PhD degree from the University of Cambridge, UK. Dr Lew has been working on magnetism and magnetic materials research for more than ten years in industrial and research laboratories. Prior to joining NTU, he worked as Research Associate at the Cavendish Laboratory.

 

Dr Lew’s research team specializes on spin-electronics or “spintronics” devices: thin film sensor growth, micro- and nano-fabrication, and micromagnetic modeling. He has extensive experience in magnetic MEMS device fabrication and has a collaborative program on the fabrication of a extracorporeal biospintronic deletion system,

 

Recently Dr Lew’s group was awarded a competitive multi-million research grant from the Singapore National Research Foundation for a non-volatile magnetic memory and logic program. He is directing a team of researchers on the projects of non-volatile magnetic solid state memory and reconfigurable magnetic logic devices.