For a number of years now quantum computers have been hyped up as leading the next revolution in computing, owing to their potential ability to perform calculations orders of magnitude faster than traditional "classical" computers. US company D-Wave has built a number of so-called quantum computers, and has teamed up in a research project with Google, but their computers remain very expensive (millions of dollars) and require cryogenic cooling.
However, if quantum decoherence (which results in the coupling of the qubits in the quantum computer to the outside world causing the quantum state to be lost from the qubit) can be substantially removed or reduced, e.g. by finding quantum systems that operate at ambient temperatures (which is one of the reasons cryogenic cooling is currently used), it may be possible to store a quantum state in a qubit for long enough to enable synchronization with multiple other qubits, such that calculations based on the superposition of multiple states can be performed, quantum computing may yet become a reality.
In the mysterious subatomic realm of quantum physics, particles can act like waves, so that they can be particle or wave or particle and wave. This is what’s known in quantum mechanics as superposition. As a result of superposition a qubit can be a 0 or 1 or 0 and 1. That means it can perform two equations at the same time. Two qubits can perform four equations. And three qubits can perform eight, and so on in an exponential expansion. That leads to some inconceivably large numbers, not to mention some mind-boggling working concepts.