Detecting tiny twists with a nanomachine

The team developed a microscopic spin-torsion device fabricated by electron beam lithography and nanomachining that mechanically measures the changes in spin states in a magnetic field. This device was operated at one tenth of a degree close to absolute zero.

The team has been working on demonstrating the opposite effect. Under the application of an external torque spin-up and spin-down electrons can be separated to two physically distinct locations, creating a spin battery. This is similar to a conventional charge battery with positive and negative polarities. When connected with an electrical path, electricity flows from one side to the other. But instead of electric current, the flow in the spin battery involves the spin – which can be used to store and manipulate information, the basis of an emerging technology called spintronics.

"The measurements with a nanoscale torsion resonator will be useful in uncovering new fundamental forces and, in theory, for characterizing torque producing molecules and DNA." said Mohanty.

Mohanty's research collaborators for the paper are Guiti Zolfagharkhani, then a graduate student at Boston University's Department of Physics, Alexi Gaidarzhy then a graduate student of BU's Department of Mechanical and Aerospace Engineering, Pascal Degiovanni of the Ecole Normale Superieure and Universite de Lyon in France, Stefan Kettemann of Jacobs University in Bremen, Germany and Peter Fulde at the Asia Pacific Center for Theoretical Physics in Namgu Pohang, Korea.

The research was supported by National Science Foundation

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Founded in 1839, Boston University is an internationally recognized institution of higher education and research. With more than 30,000 students, it is the fourth largest independent university in the United States. BU consists of 17 colleges and schools along with a number of multi-disciplinary centers and institutes which are central to the school's research and teaching mission.