Condensed Matter Physics Seminar

The concept of the Majorana fermion has been postulated more than eighty years ago; however, this elusive particle has never been observed in nature. The non-local character of the Majorana fermion can be useful for topological quantum computation. Recently, it has been recognized that topological superconductors (TSC) can support gapless Majorana state at its boundary. Examples of TSC includes not only the p_x + ip_y superconductor in 2D but also the long-known 3He superfluid B phase in 3D. In my talk, I will discuss how the Majorana nature of gapless boundary state restricts its fluctuation - absence of charge fluctuation and, for 3He-B, spin fluctuation only along the surface normal. I will show how such constraints in fluctuation channel can be experimentally detected, and recent experimental evidences for such constraints in 3He-B