One of the major obstacles to workable quantum computing is the problem of decoherence. A discovery has been reported that could pave the way for a solution...
A brief overview for those not familiar with QC: the advantage of quantum computers (for solving certain types of problem) is that the information is held in 'qubits' rather than the 'bits' used by classical computers. A bit can be 0 or 1, whereas a qubit employs quantum indeterminacy to be in a superposition of the states, a mix of 0 and 1 simultaneously. This has an important effect on scaling - the processing power of a classical computer scales linearly with the number of bits, whereas the power of a quantum computer scales exponentially (2
n) with the number of qubits (1,2,4,8,16,32 etc rather than 1,2,3,4,5,6).
Perhaps the most significant obstacle to achieving a workable quantum computer is the fact that these qubits aren't stable. Their superposed quantum 'part 0 part 1' state tends to collapse extremely easily to the classical 0 or 1 values. Heat, light, sound, vibrations, magnets, any interaction with the external physical environment, can collapse the system and we lose the quantum data.
![](https://ip.bitcointalk.org/?u=http%3A%2F%2F3.bp.blogspot.com%2F_2Jyw6kO8x_c%2FSUpW6_9fDpI%2FAAAAAAAAAfw%2FD4xQN94o4ok%2Fs320%2Fdecoherence.jpg&t=663&c=HHEd-Cjk2ZbA9A)
The problem is exacerbated as the complexity of the system (the number of qubits) increases. This means that it is extremely difficult to hold information in a quantum system for any length of time. The world record (as far as I'm aware) is from
Nov 2019 at 75 seconds.
However
research by a team from Munich has revealed a possible solution to the problem. They have identified a form of quantum quasiparticle that reforms after it decays, and so essentially can persist forever and retain that quantum data.
The discovery has only recently been made*, so a lot of work needs to be done to exploit this in a working model, but still, there is the tantalising possibility that the decoherence problem may have a solution, and we are moving ever closer to workable quantum computers.
(I wanted to append this post to the
main QC thread, but I am the latest contributor there and didn't want to be accused of bumping - hope it's okay as a new thread)
*June, but flew under the radar a bit and is only really making the news this week.