When a computer works through a task, it does so in a specific sequence of individual calculation steps. Quantum physics also enables a specially designed quantum computer to perform computations more or less simultaneously in a “superposition” of different sequences of computational steps. According to Viennese researchers, this would also be easier than expected, and the approach makes this calculator all the more superior the more complex the task is.
In quantum mechanics, systems can be in bizarre superposition states. In this way, one and the same object can be “at the same time” in two places. Like Erwin Schrödinger’s famous thought experiment, in which a cat is both dead and alive, they are in both places. In this case, physicists speak of superposition.
Order not relevant for quantum computers
If that is difficult to grasp for everyday understanding, sequences of events may also be in such a superimposed state. Whether event A occurs before event B or vice versa cannot be determined. Transferred to a quantum computer, such a computer could also perform calculations without it being determined in which order the individual calculation steps should be performed.
Such a computer, which to some extent performs calculations in parallel in all possible sequences of calculation steps, could also solve different tasks much more efficiently than another quantum computer. If one succeeds in developing such a system, one would “improve quantum computing again compared to conventional quantum computing,” said Časlav Brukner of the Institute for Quantum Optics and Quantum Information (IQOQI) Vienna of the Academy of Sciences (ÖAW) and the university from Vienna.
The more complex the task, the faster
In a “normal” quantum computer, an information carrier (qubit) runs through different quantum operations (gates) in a certain order. These gates can be represented as various “black boxes” through which a qubit – for example, a photon with quantum information – passes and undergoes a change in the process. The more such boxes a qubit passes, the more complex it is to read out the information again. If the photon passes through these boxes – vulgo individual calculations – but in a superposition of all possible series it is much faster. The speed advantage is the greater, the more complex the task.
In their work, published in the journal “Physical Review Letters,” Brukner and co-author Martin Renner were also able to disprove the assumption that more complex computations in superposition also necessarily require more complex quantum information carriers. The claim was, “The more boxes, the more dimensions the system should be,” says Brukner. The fact that this does not have to be the case makes the approach even more interesting.
Source: Krone
I’m Wayne Wickman, a professional journalist and author for Today Times Live. My specialty is covering global news and current events, offering readers a unique perspective on the world’s most pressing issues. I’m passionate about storytelling and helping people stay informed on the goings-on of our planet.
