# How researchers are mapping the future of quantum computing, using the tech of today

Pacific Northwest National Laboratory computer scientist Sriram Krishnamoorthy. (PNNL Photo) Imagine a future where new therapeutic drugs are designed far faster and at a fraction of the cost they are today, enabled by the rapidly developing field of quantum computing.

The transformation on healthcare and personalized medicine would be tremendous, yet these are hardly the only fields this novel form of computing could revolutionize. From cryptography to supply-chain optimization to advances in solid-state physics, the coming era of quantum computers could bring about enormous changes, assuming its potential can be fully realized.

Yet many hurdles still need to be overcome before all of this can happen. This one of the reasons the Pacific Northwest National Laboratory and Microsoft have teamed up to advance this nascent field.

The developer of the Q# programming language, Microsoft Quantum recently announced the creation of an intermediate bridge that will allow Q# and other languages to be used to send instructions to different quantum hardware platforms. This includes the simulations being performed on PNNL’s own powerful supercomputers, which are used to test the quantum algorithms that could one day run on those platforms. While scalable quantum computing is still years away, these simulations make it possible to design and test many of the approaches that will eventually be used.

“We have extensive experience in terms of parallel programming for supercomputers,” said PNNL computer scientist Sriram Krishnamoorthy. “The question was, how do you use these classical supercomputers to understand how a quantum algorithm and quantum architectures would behave while we build these systems?”

That’s an important question given that classical and quantum computing are so extremely different from each other. Quantum computing isn’t Classical Computing 2.0. A quantum computer is no more an improved version of a classical computer than a lightbulb is a better version of a candle. While you might use one to simulate the other, that simulation will never be perfect because they’re such fundamentally different technologies.

Classical computing is based on bits, pieces of information that are either off or on to represent a zero or one. But a quantum bit, or qubit, can represent a zero or a one or any proportion of those two values at the same time. This makes it possible to perform computations in a very different way.

However, a qubit can only do this so long as it remains in a special state known as superposition. This, along with other features of quantum behavior such as entanglement, could potentially allow quantum computing to answer all kinds of complex problems, many of which are exponential in nature. These are exactly the kind of problems that classical computers can’t readily solve — if they can solve them at all.

For instance, much of the world’s electronic privacy...