Non-local spin-transfer-torque & Paramagnetic maser device
Spin-electronics, abbreviated spintronics, is the name for a type of electronics which does not utilize the charge of the electron, but it's intrinsic angular momentum called the electron spin. One of the first and also its largest success of this field lies in the discovery of the Giant Magneto Resistance (GMR) effect which is currently being commercially used in modern day hard drives. In 2007, the Nobel price has been awarded to Albert Fert and Peter Grunberg for the discovery of this phenomena.
One of the new promises of this field is the magnetic random access memory (MRAM) which can bridge the gap between fast but volatile DRAM memory and conventional storage like the hard drive. The MRAM technique is an elegant and efficient way that relies on the transfer of electronic spins between the two magnetic layers. Electrical currents sent through an MRAM device create a torque on the magnetization of the individual layers, the so-called spin transfer torque. If this spin transfer torque is strong enough it can cause a rotation of the magnetization. The resulting memory element is called a spin transfer torque MRAM or, in short, STT-MRAM. It has the ability to greatly reduce the electrical current needed to switch these memory elements, leading to a reduced size of these elements and increased operating speeds. Although much of the physics behind spin transfer torque is still unknown, companies like Grandis are already trying to commercialize the technology.
In our metallic spintronics team we are investigating fundamental spintronic phenomena in metallic nanoscale devices. We make use of state of the art electron beam lithography (resolutions of <50 nm) to make electronic devices and study many different spintronic effects like spin-transfer-torque, spin-pumping and, recently also spin-caloritronic effects. You can read more about it in the dedicated sections.
Graphene is a one atom thick layer of graphite in which the carbon atoms are disposed in a honeycomb structure with two non-equivalent atoms. This 2D crystal has attracted enormous interest because of it's exquisite properties.The specific band structure of graphene, image on the right,
with its unique valley structure and Dirac neutrality point separating hole states from electron states, has led to the observation of new electronic transport phenomena such as anomalously quantized Hall effects, absence of weak localization and the existence of a minimum conductivity.
|Laatst gewijzigd:||23 oktober 2015 11:23|