Quantum technologies are transforming the world, offering possibilities once thought to be beyond reach. By studying energy at its smallest levels—quanta—researchers are nearing breakthroughs that could revolutionize areas like energy systems, pharmaceutical development, and secure communication. These advancements are also paving the way for quantum computers, which have the potential to outperform today's most advanced supercomputers. Despite years of intense research, scientists have yet to develop sufficiently robust quantum computing systems.

Figure 1. A Small Number of The Optical Elements Required to Construct the Full System. (Credit: Paderborn University, Martin Ratz)

However, researchers at Paderborn University have made a significant leap, constructing Europe’s largest sampling-based quantum computer: the 'PaQS' ('Paderborn Quantum Sampler') [2]. This machine was built under the Federal Ministry of Education and Research's (BMBF) PhoQuant initiative, with collaboration from industry partners including Menlo Systems, Fraunhofer IOF Jena, and Swabian Instruments, and coordinated by the industrial quantum tech company Q.ANT. A second, cloud-accessible quantum computer will soon be launched at Fraunhofer IOF in Jena. With €50 million in funding, the project brings together 13 partners from science and industry, positioning Germany at the forefront of photonic quantum computing globally [1]. Figure 1 shows a glimpse of the experimental setup focussing on the area where the squeezed light generation takes place. The photo shows a small number of the optical elements required to construct the full system.

Tackling Major Challenges in Quantum Computing

"Quantum computers are extremely sensitive to system imperfections," explains Professor Christine Silberhorn, spokesperson for the Institute for Photonic Quantum Systems (PhoQS) at Paderborn University. Quantum research is being pursued worldwide using various experimental platforms, each with its own strengths and weaknesses. Photonic networks, which use light particles called photons, operate at room temperature and can be implemented on programmable circuits, though they struggle with optical losses.

Paderborn's researchers are overcoming these challenges by leveraging Germany’s expertise in integrated photonics, creating a scalable Gaussian boson sampler. The process involves developing numerous new components, a complex task that, as Silberhorn notes, is "treading entirely new ground."

Europe’s Largest Gaussian Boson Sampling Machine: A New Era in Quantum Computing

The PaQS system developed at Paderborn is Europe’s largest Gaussian boson sampling machine. In basic terms, it measures where photons exit a vast photonic network. "Gaussian boson sampling is a photonic quantum computing model that has gained attention as a platform for building quantum devices," says Silberhorn. The team’s innovative approach integrates full system programmability, allowing them to implement any desired configuration.

In practice, light particles are distributed across a network of fiber optic cables, with the output locations of the photons measured. This technique could help solve complex problems, like protein folding or molecular state calculations, which are crucial in pharmaceutical research. The system’s programmability also allows for future applications that may arise from upcoming discoveries, offering unparalleled flexibility and a wide range of future possibilities. PaQS is currently being expanded to handle more complex computations, laying the groundwork for even greater system integration.

PaQS Powered by Squeezed Light

Building such a system requires deep knowledge of its components and the quantum phenomena involved, such as squeezing and photon entanglement, which enable the immense computational power of quantum computers. For Gaussian boson sampling, the key resource is squeezed light. Silberhorn highlights the university's strong foundation in this area, stating, "The ‘Integrated Quantum Optics’ working group at Paderborn University has a long tradition of using optical waveguides to develop highly optimized squeezed states."

The Future of Photonic Quantum Computing

Unlike quantum computers based on superconducting qubits or trapped ions, photonic quantum computers use light to perform quantum calculations, offering advantages such as scalability and high clock-speed operation. Yet, quantum computing technology remains in its early stages. Further research is needed to determine the pros and cons of various quantum platforms. Nonetheless, Paderborn University’s groundbreaking work brings the field one step closer to realizing the full potential of quantum computing.

Source: Paderborn University

References:

1. https://interestingengineering.com/innovation/quantum-computer-photonic-germany
2. https://quantumzeitgeist.com/german-researchers-unveil-europes-largest-photonic-quantum-computer/

Cite this article:

Hana M (2024), Paderborn University Leads the Way in Light-Based Quantum Technology Breakthroughs, AnaTechMaz, pp. 157