Light Quantum makes breakthrough in error-correcting quantum computing architecture
This week, PsiQuantum, which has raised a cumulative $665 million, announced a breakthrough technology for more efficient implementation of fault-tolerant quantum computing: the technology is expected to improve the runtime efficiency of compiled applications by a factor of approximately 50 [1].
01Quantum algorithms run 50 times more efficiently
This technology specifically targets algorithms for error-correcting quantum computers, rather than non-error-correcting NISQ systems. Active quantum compilation reduces the time required to run a particular application by making more efficient use of the available hardware. This is achieved by exploiting long-distance connections between different regions in a quantum computer: this technique is particularly beneficial for optical quantum computing, where long-distance connections can be achieved using conventional optical fibers.
The development of PsiQuantum allows a more beneficial reuse of otherwise idle computational resources (inactive computational volume). In many commercial applications using quantum algorithms, this has a significant impact on hardware uptime and efficiency. It is estimated that optimizing the amount of activity can improve the operations required by some algorithms by a factor of about 50.
This is a very significant achievement by our fault-tolerant team," said Pete Shadbolt, chief scientific officer and co-founder of PsiQuantum. the 50-fold improvement means that quantum applications that previously took a month to execute on a future optical quantum computer can now run in less than a day. "
The improvements provided can be extended to many different quantum algorithms of practical importance. This brings a broader diversity of useful quantum applications within the context of future quantum computing technologies.
02Examples of quantum computing optimization
Examples show the structure of a quantum computation executed on an active quantum computer with 12 quantum bit blocks. (a) The quantum computation corresponds to a sequence of 5 operations with 6 quantum bits, where each operation has a representation of a network of logical blocks. (b) In the first logical cycle, operations 1 and 2 are executed. (c) In the second logical cycle, only operation 3 is executed. (d) In the third logical cycle, operations 4 and 5 are executed.
(a) A modified version of the ripple-bearing adder (adder) circuit. (b) Each repetitive segment of this adder has an effective volume of 22 blocks in addition to the volume required to generate the CCZ state. (c) The compressed ZX diagram can be used to verify that the two diagrams describe the same operation.
Results of numerical simulations
A specific example of work occurs in the case of code-breaking, such as the application involving the Shor algorithm. According to the assumptions given by PsiQuantum in the paper [2], it is estimated that by using this technique, the time required to break very strong (2048-bit) encrypted RSA keys is reduced to about 9 hours on a future optical quantum computer running at 1ns operation cycle. While the company continues to develop the massively fault-tolerant quantum computers needed to perform this application, this result significantly reduces the requirements for this future system.
The approach has additional implications for the more widespread and optimal use of quantum computing. As described by Naomi Nickerson, vice president of quantum architecture at PsiQuantum.
"This development also has implications given the ability of optical quantum computers to exploit the trade-off between computational resources and computational runtime. Active quantum technology reduces the required computation time, which can translate into reduced hardware resources using techniques such as photonic interleaving. This may also have practical implications in terms of allowing programs to run in the same amount of time using less hardware. While the benefits of this approach can be realized with any technology capable of connecting distant quantum bits, this is challenging for many current approaches, and active volume architectures are particularly well suited for optical quantum bits connected using optical fibers."
"We believe that this result will have important implications for ongoing, worldwide efforts to analyze known quantum algorithms for specific problem instances and find the best way to compile them. These implementation details are critical when aiming to deliver commercially useful applications."
Jeremy O'Brien, CEO and co-founder of PsiQuantum, said, "This improvement is another exciting step in bringing useful quantum applications into the scope of near-future hardware. We have a great team of quantum architects and quantum engineers working to optimize software for public-scale quantum computers. We expect to see resource requirements continue to decline along with our hardware improvements."
About PsiQuantum
Driven by breakthroughs in silicon photonics and fault-tolerant quantum architectures, PsiQuantum is building the first common-scale quantum computers to address some of the world's most important challenges.PsiQuantum's approach, based on optical quantum bits, offers significant advantages in providing the scale required for fault-tolerant, general-purpose quantum computers. With quantum chips now being produced in the world's leading semiconductor fabs, PsiQuantum is uniquely positioned to deliver quantum capabilities that will drive advances in climate technology, pharmaceuticals, healthcare, finance, energy, agriculture, transportation, communications and more.
Reference Links：
[1]https://www.businesswire.com/news/home/20221201005956/en/PsiQuantum-Announces-Breakthrough-in-Architectures-for-Error-Corrected-Quantum-Computing
[2]https://arxiv.org/abs/2211.15465
