When fully realized, quantum computers will empower humanity to solve problems that today seem unsolvable. But even impossible problems have a way of proving possible given enough time. Before the Wright brothers rewrote the future, it seemed impossible for humans to fly.
One of the major limitations of today’s qubits is that they can be decohealed very rapidly. It goes from providing real work to having calculations not providing accurate results. So this is another type of race against time. A researcher from the Institute for Molecular Science of Japan leaps to the top (opens in new tab) By breaking the record for the fastest two-qubit gate operation ever performed in quantum computing. (opens in new tab)
A qubit, as the name suggests, is the quantum equivalent of the binary bit that drove our technological revolution. A special power of qubits is that they don’t have to be fixed at 1. Also zero. Instead, there are additional functions that can represent both. When zero. This allows qubits to do much more work per unit time than basic bits. This allowed him to perform in six minutes what real-world calculations (such as BMW’s Sensor Placement Challenge) would take exponentially longer on the most powerful computers.
The two-qubit gate operation is the most basic (and first on a favorable scale) qubit arrangement, requiring two qubits to be entangled. This basically means that their state is shared (or coherent). However, as we have seen, today’s quantum systems tend to be susceptible to noise (such as environmental radiation). The noise can lead their tangles into decohears, causing whatever operation you’re doing to fail (remember when you overclocked your PC too much and Prime95 returned an error? is one of
There are two ways to deal with this issue. Either perform the operation faster (usually in microseconds before decoherence starts) or extend the qubit entanglement lifetime. Japanese researchers adopted the former approach.
Using a laser, the researchers blasted two atomic qubits made from the element rubidium (the absolute smallest particle of the basic unit, atoms naturally lean towards the quantum role) to absolute zero (-273.15 °C). Cooled to near temperature.
This is not the only absolute zero technique for processing qubits. Its physics are related to the speed at which molecules interact with each other. The higher the temperature, the faster the interaction and the easier it is to excite. Cooling them to an equivalent vacuum, on the other hand, is akin to hibernating them, slowing their interaction with each other and with the environment itself, resulting in longer coherence times. On the other hand, you can pop it out of that state with a big enough thrust, but you might be able to stab it with one or two needles.
The researchers then used optical tweezers to pin these atoms within a micrometer of each other, and the final laser manipulated the qubits at intervals of 10 picoseconds (trillionths of a second). Using this technique, the researchers successfully performed a quantum gate operation, completing it in 6.5 nanoseconds. This is less than half the previous fastest two-qubit gate operation, which took 15 ns.
1,000 nanoseconds fits into 1 microsecond, so there was plenty of time between the qubits getting entangled and the system decohealing them to perform the computation.
The researchers’ work has not yet solved the problem of quantum computing, but it is a step in the right direction. At the very least, it indicates that there are still faster operating speeds to be unlocked in the quantum realm, ultimately requiring scaling of the performance available from this emerging computing solution.
Systems created by researchers have certain practical caveats. One is that we could only entangle and operate on two qubits that were entangled. For example, IBM plans to introduce 433 qubits. Osprey Quantum Processing Unit (QPU) of the year.
Another thing to note is that the rubidium atomic qubits employed by the researchers, and the technology that allowed them to break the world record, require the system to be cooled to absolute zero. This is a costly effort and difficult to replicate in high-performance computing (HPC) and other environments around the world.
There are many runners, and certain technologies will arguably end up developing slower than others, eating the proverbial dust of capital and time investments. Until then (just as semiconductors were silicon when silicon was introduced), the problem remains open.
