Quantum weeknotes 1

University of Oxford Department of Physics Optical lab

Image illustrating the Department of Physics page describing their quantum networking research

This is my collection of references to examples of explanations of quantum networking.

There are roughly three categories of audience

  • physicists and people who have experience with quantum mechanics
  • people who understand conventional computer networking, who start from ‘How many gigabits per second, with what delay, and what error characteristics’ and go on to ‘what do the connectors look like’ ?
  • people who are unfamiliar with both computing and networking but are interested when I say ‘I’m working with a new company’ and for whom I want a description that doesn’t start from ‘entanglement is like magic operations at a distance’

These audiences are not disjoint: any material for the non-specialists in the topic has to be accurate and precise. This is a rapidly moving field so that references to material from previous years needs to indicate that.

The Oxford description above is for physicists. So is the description from Imperial College, about ‘quantum dots’ producing (non-entangled) photons, which were then passed to a quantum memory system that stored the photons within a cloud of rubidium atoms. A laser turned the memory ‘on’ and ‘off’, allowing the photons to be stored and released on demand.

Bell Labs (of storied history) is now part of Nokia. The Register (a source of long standing for networking people) has a good attempt at addressing their audience with the description of the topological qubits Bell Labs are building, which require cryogenics. Doesn’t at all answer questions about speeds and feeds, though.

McKinsey has a description which summarizes to ‘this is still research’, but follow the money. Lists chip developments from Google (Willow) and Microsoft (Majorana 1); AWS’s Ocelot for cat qubits.

Cisco, Nvidia, and IBM all have labs with working hardware.

Useful summary for computing and network people :

  • Quantum computing. Quantum computing is a computing paradigm leveraging the laws of quantum mechanics to significantly improve the performance of certain applications and to enable new territories of computing.
  • Quantum communication. Quantum communication is the secure transfer of quantum information across distances.
  • Quantum key distribution (QKD). QKD is the use of quantum technology to securely share a secret key that can be used with classical encryption algorithms.
  • Quantum sensing. Quantum sensing uses a new generation of sensors based on quantum systems that provide measurements of various quantities—for example, electromagnetic fields, gravity, and time. Quantum sensors may be orders of magnitude more sensitive than classical sensors.

Caltech explanation “Entanglement can also occur among hundreds, millions, and even more particles. The phenomenon is thought to take place throughout nature, among the atoms and molecules in living species and within metals and other materials. When hundreds of particles become entangled, they still act as one unified object. Like a flock of birds, the particles become a whole entity unto itself without being in direct contact with one another.”

DCVC annual report

Reasons for long term optimism (beyond the current political horizon) about the US and world economy. I met Matt Ocko back in 2014, when DCVC invested in a hardware startup which was wildly overambitious about what it could achieve. Since then he has very substantially scaled the company. Here is it’s third annual report.

Pulling out just two examples

– investment in Mythic, a maker of matrix processors enabling parameters used in the training and inference phases of a generative AI program such as a large language model to be  stored directly in the processor rather than in separate memory, so as to get “more compute in more places that works faster and for less power” 

– investment in Q-CTRL, which builds error suppression software that improves the performance of quantum computers, and has pioneered a new generation of quantum-enabled navigation technology

Quantum computing

Snapshot, November 2019

Research
State of the art summary, references and curated comments Scott Aaronson https://www.scottaaronson.com/blog/

Small companies

IonQ Trapped ion computing
PsiQ Silicon photonics https://psiquantum.com/
QCWare Software services
Rigetti Quantum cloud services
Xanadu Quantum photonic processors https://www.xanadu.ai/

Large companies
Google https://ai.google/research/teams/applied-science/quantum/
IBM https://www.ibm.com/quantum-computing/
Microsoft https://www.microsoft.com/en-us/quantum/
Honeywell Trapped ion Qbits https://www.honeywell.com/en-us/company/quantum

Upcoming conference

https://q2b.qcware.com/ San Jose 10 -12 December 2019