n<\/p>\n
Why did you originally set up Phasecraft?<\/h3>\n
n<\/p>\n
We founded Phasecraft because quantum computing was reaching the point where quantum-computing hardware was no longer just a toy system, but pushing the boundaries of what could be done on conventional computers. We wanted to try to develop the algorithms needed to make use of that early-stage hardware and make quantum applications a reality. That’s a huge challenge scientifically, but a fascinating one to be involved in.<\/p>\n
n<\/p>\n
How big is the company at the moment?<\/h3>\n
n<\/p>\n
We currently have about 20 full-time staff<\/a>, roughly a third of whom have a background in quantum computing or quantum information theory, a third in materials science, condensed matter and chemistry, and a third on the computing side. They all have a knowledge of quantum computing, but are also very, very good at \u2013 and love \u2013 programming this stuff, and implementing it, and getting it working on the hardware.<\/p>\n n<\/p>\n We sponsor PhD students who are at places like University College London and the University of Bristol but who work directly here in the company\u2019s offices. We also have lots of interns \u2013 both undergraduates and PhD students. We’re very focused on research and development at the moment. But as useful applications come online, I expect things to become much more commercial in nature.<\/p>\n n<\/p>\n n<\/p>\n Hardware is extremely important and deserves the attention it’s been given, involving as it does some fascinating physics, materials science and engineering. But for us on the software side, it\u2019s all about coming up with clever mathematical ideas to make algorithms more efficient and work on today\u2019s early-stage, small-scale quantum devices. In fact, we\u2019re more likely to make progress through better algorithms than by waiting for improvements in hardware.<\/p>\n n<\/p>\n Even if quantum hardware grew exponentially, it could be a decade before you could do anything useful with it. Working on algorithms also doesn\u2019t require expensive cryostats, dilution refrigerators, liquid helium or chips \u2013 just a bunch of really smart people thinking deeply, which is what we have at Phasecraft. A few years ago, for example, we developed algorithms for simulating the time dynamics of quantum systems that were about six orders of magnitude better than those from Google and Microsoft.<\/p>\n n<\/p>\n n<\/p>\n Noise and errors are the bane of all quantum applications on real hardware. There have been some incredible improvements to hardware, but we can\u2019t assume quantum computers are perfect, as we can with classical devices. So with everything we do in Phasecraft, we have to think in terms of imperfect, noisy quantum computers that have errors. Run any computation and the errors build up so fast that you’re just getting noise \u2013 random data \u2013 out, and you’ve lost all of the quantum information.<\/p>\n n<\/p>\n To get round this problem, it\u2019s critical to make algorithms as efficient as possible and make them less sensitive or susceptible to noise. It\u2019s true that in the 1990s Peter Shor<\/a> developed the concept of quantum error correction and the fault-tolerant threshold theorem<\/a>, which shows, theoretically, that even on noisy quantum computers, you can run arbitrarily long quantum computation calculations. But that requires such huge numbers of qubits that we can\u2019t count on this as a solution.<\/p>\n n<\/p>\nWould you say quantum software has been ignored in favour of all the hype and excitement of developing new qubits and processor technologies?<\/h3>\n
Quantum processors are noisy, which means they quickly lose coherence and make calculations impossible. How do you develop practical algorithms to run on imperfect devices?<\/h3>\n
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