ELFT HÍRADÓ

[tcsaba AT eik.bme.hu]

                                    MEGHÍVÓ

              a BME Fizikai Intézete Elméleti Fizika Tanszékének

                               szemináriumára:


                                Randy Fishman
                           Oak Ridge National Lab


              "Room Temperature Optical Diode Effect in BiFeO3"


A microscopic model for the room-temperature multiferroic BiFeO3 that
includes two Dzyaloshinskii-Moriya interactions and single-ion anisotropy
along the ferroelectric polarization predicts both the zero-field
spectroscopic modes as well as their splitting and evolution in a magnetic
field.  Due to simultaneously broken time-reversal and spatial-inversion
symmetries, the absorption of light changes as the magnetic field or the
direction of light propagation is reversed.  We conclude that the
directional dichroism in BiFeO3 is dominated by the spin-current
polarization and is insensitive to the polarizations induced by
magnetostriction and easy-axis anisotropy.  Since some modes are almost
transparent to light traveling in one direction but opaque for light
traveling in the opposite direction, BiFeO3 can be used as a
room-temperature optical diode at certain frequencies in the GHz to THz
range.

Helye: BME Elméleti Fizika Tanszék,
Budafoki út 8. F-épület, III lépcsöház, szemináriumi szoba
Ideje: 2015. június 19. péntek, 10:15.



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