Topological spintronics

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TOPOLOGICAL SPINTRONICS

WELCOMETOPOLOGICAL SPINTRONICSGUIDED BY, SUBMITTED BY, Mrs.RAFEEKHA M.J. ANCY RAJU ASST.PROFESSOR S7 EC A ECE DEPARTMENT ROLL NO:4

22-08-2014 1 INTRODUCTIONSPINTRONICSTOPOLOGICAL INSULATORSMB6 KONDO EFFECTANGLE RESOLVED PHOTOEMISSION SPECTROSCOPYADVANTAGES DISADVANTAGESAPPLICATIONSFUTURE SCOPECONCLUSIONREFERENCESCONTENTS 22-08-2014 2 INTRODUCTIONThe discovery of new materials with novel properties is one of the most fascinating aspects of physics.Such findings lead to new research area in spintronicsA very recent example of new materials is the topological insulators.

22-08-2014 3 SPINTRONICS

Conventional electronics uses charge of electron.Spin based electronics incorporates spin of electron.Spin is the intrinsic property of an electron.Spin can exist one of the two states up or down.

22-08-2014 4 TOPOLOGICAL INSULATORControlling electron spin can be achieved with materials called topological insulators.Behave as insulators on the inside,but are highly conductive on their surface.

22-08-2014 5A new class of topological insulator is Topological Kondo Insulator .As insulators are cooled to absolute zero,their ability to insulate effectively becomes infinite.Under these conditions,some insulators atypically retain a tiny bit of conductivity.These materials,termed Kondo Insulators.In contrast to other 3D topological inulator,a TKI is truly insulating in the bulk.The strong electron correlations are present in the system,which may interact with the novel topological phase.

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22-08-2014 7 SMB6

Topological kondo insulator.It directly measures electron spin.At high temperature(above 50k),its properties are typical of a kondo metal,with metalic electrical conductivity characterised by strong electron scattering.At low temperature, it behaves as a non magnetic insulator.Its insulating behaviour based on Kondo effect. 22-08-2014 8Scattering of conduction electrons in a metal due to magnetic impurities resulting a charateristics change in resistivity with temperature. The effect arises from the interaction between a single magnetic atom such as cobalt,and the many electrons in an otherwise non-magnetic metal.

KONDO EFFECT 22-08-2014 9Such an impurity typically has an intrinsic spin that interact with the electron.It prevents the flow of electrons from being destroyed by irrgularities in the metal structure Making SmB6 a very robust and efficient topological kondo insulator.

Cont 22-08-2014 10 ANGLE RESOLVED PHOTOEMISSION SPECTROSCOPY 22-08-2014 11

22-08-2014 12 Can control electron spin.Increasing memory storage capacity.Increasing processing power.Consume less power.

ADVANTAGES 22-08-2014 1 3 Manufacturing and implementing topological insulator materials has been limited.

DISADVANTAGES 22-08-2014 14 APPLICATIONSUltra low power electronics and spintronics devices.Optoelectronic applications.Memory storage and magnetic sensor applications.Majorna fermion used in quantum computation.

22-08-2014 15 FUTURE SCOPE

Skyrmions for quantum computing 22-08-2014 16Magnetization of skyrmion

22-08-2014 1 7The research on today on the topological insulators materials.It is the best mechanism for creating ever smaller and faster devices. It offers an exciting stepping stone into the a new era of technologies.

CONCLUSION 22-08-2014 1 8 Nature Communication 30 July 2014 Ecole Polytechnique, Federale de Lausanne.Josh Schaefferkotter,Introduction of spintronics(2007).Ando.Y ,Topological insulator materials(2013).M Z Hasen and C L Kane (2010) Colloqium:topological Insulators.J E Moore (2010), The birth of Topological insulatorREFERENCES22-08-2014 19THANK YOU