New material for quantum computing discovered out of the blue

A common blue pigment used in the £5 note could have an important role to play in the development of a quantum computer, according to a paper published today in the journal Nature.

The pigment, copper phthalocyanine (CuPc), which is similar to the light harvesting section of the chlorophyll molecule, is a low-cost organic semiconductor that is found in many household products. Crucially, it can be processed into a thin film that can be readily used for device fabrication, a significant advantage over similar materials that have been studied previously.

Now, researchers from the London Centre for Nanotechnology at UCL and the University of British Columbia have shown that the electrons in CuPc can remain in 'superposition' – an intrinsically quantum effect where the electron exists in two states at once - for surprisingly long times, showing this simple dye molecule has potential as a medium for quantum technologies.