A group of physicists have created miniature detector of spin waves, consisting of 11 atoms. The developed detector has a memory of several seconds, which makes it compatible with modern methods of measurement using scanning tunneling microscopes. Work published in the journal Nature Communications Physics.
Operation of spintronics devices based on magnons, or spin waves, which are the elementary magnetic excitation of the spins (on spintronics and its applications can be found in our article “Magnetism electricity”). Unfortunately, control of spin waves in nano-devices is incredibly difficult. Apart from the fact that waves travel extremely fast, they can move in opposite directions at the same time due to its quantum nature. To control spin waves, it is necessary to begin to learn to observe their dynamics with high precision.
For the measurement of magnons in atomic structures are circuit detection using atomic probe in a scanning microscope. Unfortunately, the modern scanning microscopes are often not able to catch a quick spin waves: to probe the dynamic response, which is faster than the measurement time of the microscope, it is necessary to develop an intermediate detector with memory to save the response until then, until it is measured by the microscope. In other words, the detector memory needs to record information on the time scale available for scanning microscope (on the order of seconds). However, the development of such a system is a serious challenge for experimental physicists.
A group of researchers from University of Delft under the supervision of Professor Otta sander (Sander Otte) has created such intermediate detector to study the dynamics of magnons. The detector is a quantum system, is very sensitive to the excitations: the atoms of iron are arranged in a chain, capable of measuring the passing spin wave and store the measurement result to a few seconds after the fact of passage of the wave. The device comprises three atoms in the input layer and eight atoms in the output.