Detecting quantum errors

Quantum computers are a reality from a scientific point of view but are far from there from a technical and engineering point of view: in other word we know how they work, what we can do with them but we have not been able, so far, to build one that really works.
There have been implementations of quantum computers, like D-Wave, but not everybody has accepted them as the real thing.
The problem with quantum computer is the fleeting existence of their state.
When you use a classical computer, a von Neumann machine, you know that there is a value stored in a memory or in the processing unit and you know that you can access it at your own pace (almost). In quantum computer the technology we have is not able, yet, to guarantee this kind of stability. Quantum information is fragile and it suffer from interference with many things, like temperature, fields, atomic level defects in materials … This is know as the problem of decoherence that manifests itself in bit-flipping (a bit changes its value) and phase-flip (contributing to the assessment of the quantum state).
Researchers at IBM have been able to create a circuit that can at the same time detect both bit-flip and phase-flip. Up until now it was only possible to detect one or the other.
Even better the circuit can scale, that is support more than the 4 QBits it is supporting today. A good step forward but we are not there … yet.

About Roberto Saracco

Roberto Saracco fell in love with technology and its implications long time ago. His background is in math and computer science. Until April 2017 he led the EIT Digital Italian Node and then was head of the Industrial Doctoral School of EIT Digital up to September 2018. Previously, up to December 2011 he was the Director of the Telecom Italia Future Centre in Venice, looking at the interplay of technology evolution, economics and society. At the turn of the century he led a World Bank-Infodev project to stimulate entrepreneurship in Latin America. He is a senior member of IEEE where he leads the New Initiative Committee and co-chairs the Digital Reality Initiative. He is a member of the IEEE in 2050 Ad Hoc Committee. He teaches a Master course on Technology Forecasting and Market impact at the University of Trento. He has published over 100 papers in journals and magazines and 14 books.