The
Villum Experiment programme is designed to back bold, high-risk ideas with the potential for major breakthroughs. That is exactly what Zhdanov’s project is, taking on one of the toughest challenges in quantum technology: how to detect individual particles of light – photons – quickly, accurately, and under room temperature. These detectors are essential for quantum computers and ultra-secure quantum communication networks, which promise faster computing and unhackable data transmission. Reduced temperature requirements have the potential to make quantum technologies more accessible and thus see broader adoption.
To tackle this, Zhdanov is exploring a new approach using nonlinear integrated devices – tiny optical chips that can manipulate light in complex ways – as next-generation photon detectors. These chips could potentially tell not just whether a photon has arrived, but how many have arrived, and do it with less dead time than current superconducting detectors.
Squeezed light
At the heart of the research is the concept of “quantum squeezing” or “squeezed light.” Light is never perfectly steady and always has natural fuzziness or noise. Squeezed light is a special form of light, where noise is redistributed between its two parameters (amplitude and phase) to reduce the noise of one of them. In quantum physics, by squeezing the light, we can make its behavior more predictable and get much more accurate measurements.
A light guide
To create this special kind of light, Zhdanov uses a device called an optical parametric amplifier – basically, a tool that takes in laser light and transforms it using special materials. When the laser interacts with these materials, it produces linked pairs of photons that reduce the fuzziness normally found in light. The process known as squeezing.
The amplifiers are made from very thin layers of materials like lithium niobate and lithium tantalate, which are especially good at manipulating light. Because these materials are so efficient, this will allow us to build powerful, compact optical devices that could become key components in future quantum technologies.
Aim
Zhdanov’s main goal is to understand the performance limits of these devices – how efficiently they can detect photons, how often they make errors, how consistent their timing is, and what the power requirements are. By mapping out these limits, we can see whether these new designs are suitable for real-world quantum applications.
If successful, this research could lead to photon detectors that work at room temperature, unlike today’s versions that need to be cooled below -269°C – almost absolute zero. This would make quantum computers and communication systems far cheaper, more compact, and easier to scale, helping move quantum technology from the lab to everyday use in secure communications, high-performance computing, and advanced sensing.
