Quantum computing company PsiQuantum is speeding up efforts to build a large-scale quantum computer using photons. MIT Technology Review reported on July 14 that the company is pursuing an approach that makes chips in existing semiconductor production facilities and connects about 100 cooling cabinets to implement a practical-scale system.

PsiQuantum was founded in 2016 by four physicists from British universities. Unlike existing quantum computers that remained small prototypes, it set out from the start to target a large commercial system. It raised $1 billion last year and began building a hub in Chicago with a local government. It is also preparing a second hub in Australia. The company said it would make the facility operational by 2027, but that refers to preparing for cooling equipment and hardware installation and does not mean completing a full-scale quantum computer.

PsiQuantum's differentiator is that it chose photons for qubits instead of superconducting circuits or electrons. Photons can maintain quantum states for a long time, but they do not easily interact with each other, making computational control difficult. PsiQuantum has set a strategy to solve this with a network of optical switches, beam splitters and detectors. It plans to create photons with lasers, bind them in an entangled state, perform operations in a circuit and then measure single photons at the end.

At its Milpitas, California, facility, it is testing 250 chips in each of three connected cabinets. The next stage is to connect about 100 cabinets after a large cooling system is installed at the Australia hub. The equipment currently operates at 2K, and a liquid helium-based cooling system is one of the company's major investment items.

Its supply chain strategy is also a feature. PsiQuantum makes barium titanate itself and sends it to GlobalFoundries in Malta, New York, to produce chips. It aims to boost mass-production efficiency by using a structure similar to supply chains for silicon photonics chips used in data centres.

PsiQuantum, together with Microsoft, is one of two companies that have reached stage 3 of a U.S. government evaluation programme for quantum companies. Still, some outside assessments say it is not easy to verify the technology. The company is also preparing algorithms in materials, batteries and aerospace with Lockheed Martin, Mercedes and Airbus. Vice President Philippe Ernst (필리프 에른스트) said the goal is to cut the calculation time for P450 enzyme related to drug breakdown to as little as 4 minutes.