Quantum computing has been the unicorn of computer research for a while now. It may be able to solve complex problems that today's computers would take hundreds of thousands of years to solve.
Recently, IBM has recently taken a rather large step towards making quantum computing a reality in the form of their new 5-qubit, or quantum bit, processor.
IBM's quantum computer. Image courtesy of IBM.
To understand what 5 qubits means in the grand scheme of quantum computing, consider this: Dario Gil, Vice President of Science and Solutions at IBM Research, says that it would be impossible for any classical computer to emulate what a 50-qubit quantum system could accomplish.
The innovation doesn't stop there. IBM also connected their new processor to the cloud so that anyone can test it out. In the long climb to having a common place quantum computer, this is one of the first concrete steps to widespread use of quantum computing.
What is quantum computing?
If you don't already understand about conventional computers and digital logic, check these out before reading the rest of the article.
The first large difference between quantum computing and classic computing is the base unit of logic operations, which is the qubit. A qubit is different than a traditional bit in that it utilizes quantum mechanics to do operations.
Superposition, or being in two states at once, is a normal state for a qubit to exhibit. A more conventional way of thinking about superposition is to imagine a bit being both a 1 and a 0 at the same moment in time. Superposition is one of the key ingredients of a quantum computer; this leads to being able to solve some extremely complex problems by being able to account for every single possibility.
One somewhat scary example is that a quantum computer could be able to brute force passwords that would take conventional computers millennia to crack—in a few hours or even minutes.
There are vast complexities of physics behind quantum machines, but luckily IBM has not only given us a tutorial for their computer, but also a general background for learning more about quantum computers which can be found here.
A Bloch sphere representation of a qubit. Image courtesy of IBM.
Since we are now looking at quantum bits, we also then get some quantum gates. These function in principle the same way traditional logic gates do, but they also incorporate some properties to fully use the properties of these qubits.
One such gate is the CNOT, also the first quantum gate IBM introduces in its tutorial. It stands for "Controlled NOT" and, as the name implies, uses one qubit to influence the other. In classical computing, this is almost the same as an XOR gate in terms of the logic table.
If you'd like to learn more about advances in quantum logic gates, read about Oxford University's quantum logic gate with 99.9% precision.
Using IBM's Quantum Composer
This can all be tested out in the Quantum Composer, which can be either a simulation of a quantum computer or the actual thing. No, you didn't read that wrong. You, dear reader, can program and run a quantum computer! Well, you can run the 5-bit processor and do limited operations. As there is only one computer to run everyone's commands on, your experiments with the cloud-based processor will sit in a queue for up to 24 hours.
IBM then looks at the results and gives two options for looking at the data: a normal histogram and their Quantum Sphere representation or QSphere.
An image of the IBM Quantum Composer. Image courtesy of IBM.
Quantum Computing for Quantum Issues
We can't know for certain the true capabilities of a quantum computer until we've built one. However, experts have already been speculating about the kinds of issues that quantum computers could help solve.
Simulations of the universe are some of the most difficult tasks that classical computers are asked to run. As the amounts of specific details in these simulations increase, however, classical computers begin to struggle.
Quantum computers are able to simulate more of the universe by exploiting their inherent properties of quantum physics. Quantum parallelism allows a quantum computer to simulate multiple processes at once.
Quantum parallelism, unlike classical parallelism, is capable of doing multiple classical operations at once by doing one operation on a qubit. This is one of the properties of quantum mechanics that many people find counterintuitive.
Another way to understand this is presented by Jerry Chow, the manager of the Experimental Quantum Computing research team at IBM. Caffeine molecules, Chow says, are so complex that classical computers can't simulate them with 1s and 0s (classic bits).
In effect, simulating caffeine in a program is a quantum problem suitable for quantum computers. To this end, the creation of functioning quantum computers could allow for extraordinary advances in designing pharmaceuticals and treating diseases.
We will only begin to uncover more interesting ideas and potential solutions to be used with a quantum computer as we develop the technology. The future is strange and bright, yet may be clarified with a computation with a quantum computer.
Want to get started in your quantum computing experience? Click here to find out more!
Need some inspiration? Check out this video of the Quantum Composer running an experiment on Grover's Search Algorithm: