Majorana fermions tagged posts

A device that can separate and recombine pairs of electrons may offer a way to study an unusual form of superconductivity, according to RIKEN physicists. This superconducting state would involve exotic particles, Majorana fermions that could prove useful in developing quantum computers.

In conventional superconductors, electrical current flows with no resistance due to electrons teaming up to make ‘Cooper pairs’. A superconductor touching a normal conductor can sometimes induce superconductivity in that conductor through Cooper pairs from the superconductor penetrating the normal conductor.

Now, Sadashige Matsuo of the RIKEN Center for Emergent Matter Science and collea...

The aluminum plates were attached to the topological insulator using platinum. The picture (scale bar: 200?nm) shows one of the devices used in the experiment. Because of the stress, induced by various cool downs, a clear buckling feature appears in the nanogap of the device. This modification is causing the characteristics of the superconducting pairs of electron to vary in different directions, a signature of unconventional superconductivity. Credit: Thilo Bauch and Floriana Lombardi/Chalmers University of Technology

They have probably succeeded in creating a topological superconductor. With their insensitivity to decoherence what are known as Majorana particles could become stable building blocks of a quantum computer...

The excitation of a spin liquid on a honeycomb lattice with neutrons. Credit: Image courtesy of University of Cambridge

This state, quantum spin liquid, causes electrons – thought to be indivisible building blocks of nature – to break into pieces. The researchers, including physicists from the Uni of Cambridge, measured the first signatures of these fractional particles, known as Majorana fermions, in a 2D material with a structure similar to graphene. Their experimental results successfully matched with one of the main theoretical models for a quantum spin liquid, known as a Kitaev model. Quantum spin liquids are mysterious states of matter which are thought to be hiding in certain magnetic materials, but had not been conclusively sighted in nature.

The observation of one of their most in...