Xavi Marti

Charles University

In 1936, a 21-year old student wrote: "In the circuits of complex electrical systems it is frequently necessary to make intrincate interconnections of relays and switches". After showing how to simplify them, he concluded: "It is possible to perform [any] complex functions by means of such circuits". [1]

In 1947, Bell Labs announced a compact electrical-in electrical-out switch based on semiconductors - the transistor. Recall that virtually any experience that surrounds us can be translated from/to electrical signals: light, sound, pressure (displacement), information, ... as well as transmitted long distances. It was a matter of time to fabricate any compact machine with any purpose.

But the main character, the electron, has "spin". The marriage of charge and spin in metals, the socalled giant magnetoresistance, led to an improvement in data storage. But by using semiconductors there may be yet the possibility to edit the functions that process the data. Recall that, in our brains, both our data and functions change by re-arranging our electrical switches (neurons).

In the last decade, spin-semiconductor-based switches have been developed using ferromagnets but, unfortunately, operating below room temperature. In 45 minutes, we will discuss the alternatives with antiferromagnetic semicondcutors. Our recent work comprises the demonstration that materials for room temperature operation can be prepared [2] and the manipulation of antiferrromagnetic-based switches [3].

[1] Claude Shannon, Master thesis, "A symbolic analysis of relay and switching circuits". [2] T. Jungwirth, et al., Phys. Rev. B 83, 035321 (2011) [3] B-G. Park, et al., Nature Materials 10, 347–351 (2011)

4:00 p.m., Physics Research Building (PRB), Room 1080

Reception at 3:45 p.m., Atrium, PRB