CORDIS - Forschungsergebnisse der EU
CORDIS

Quantum readout techniques and technologies

Periodic Reporting for period 3 - QUARTET (Quantum readout techniques and technologies)

Berichtszeitraum: 2021-11-01 bis 2023-04-30

Quantum information science, ready to lead the next wave of quantum technologies, holds great promise for society. Its crucial applications include handling classical data,
which is growing too complex for conventional methods, posing challenges in business, healthcare, and security.

This project's overarching goal is to leverage the laws of quantum mechanics and the resources of quantum information to engineer powerful methodologies
for the extraction and identification of classical data from physical systems. More specifically, we strive to demonstrate a significant quantum enhancement in several areas, including:

1. Extraction of classical data from optical digital memories (quantum reading)
2. Identification of classical patterns (quantum-enhanced pattern recognition)
3. Optical measurement of concentration in delicate biomedical samples (quantum bio-probing)
4. Microwave detection of target objects (microwave quantum illumination or quantum radar)

Achieving these objectives begins with refining foundational theoretical models: quantum hypothesis testing and quantum metrology.
We then progressively expand these basic models into technical studies and empirical proof-of-principle demonstrations of these quantum technologies.

The ability to efficiently read data bits using a few photons could pave the way for new types of organic memories and photodegradable materials.
This capability is particularly beneficial at high frequencies, where dye-based supports become highly photosensitive. The fundamental operation mechanism
may foster the development of more efficient technologies for data storage and retrieval, thus boosting data transfer rates and storage capacities.

Given their superior performance at ultra-low energies, quantum reading and pattern recognition may have far-reaching applications in biology and medicine.
For instance, the potential exists for fully non-invasive probing of delicate biological samples or human tissues, such as recognizing patterns related to bacterial growth.
These patterns could be identified using non-invasive quantum-correlated light, a technique where classical light might either cause damage or fail to extract meaningful information.
Such breakthroughs could inspire future non-invasive methods for biomedical imaging.

Moreover, the development of a short-range quantum radar could potentially revolutionize environmental scanning systems,
offering continuous, low-power monitoring both for safety and security purposes.
The consortium has made significant advances in quantum information, delivering both theoretical and experimental breakthroughs.

Theoretically, we have progressed in the areas of quantum hypothesis testing and quantum metrology. We pioneered protocols for quantum-enhanced information retrieval
from physical systems, spanning applications in digital memory, pattern recognition, biological probing, and target detection. We have identified conditions for achieving quantum advantages in these tasks.

We have established maximum limits for adaptive discrimination of quantum channels, demonstrating how these can be reached for channels with appropriate symmetries.
We showed that cost-effective quantum states and measurements can yield a quantum advantage in their discrimination, providing the foundation for our experimental realizations related to cell readout, target detection, and biological sensing.

Our quantum reading experiment showed enhanced information retrieval from a memory cell using entangled light. Importantly, we proved this quantum advantage can be realized with practical photo-detection techniques.
We also extended this setup for conformance testing, detecting a defective "box" within a series. These results hold the potential to revolutionize the industry by harnessing quantum resources for superior data extraction.

Our quantum-enhanced pattern recognition experiment exhibited superior digit identification amidst the noise, presenting an image classification advantage over optimal classical strategies.
This advancement could enhance information extraction from unfamiliar patterns and images, benefiting surveillance and diagnostics.

We've also shown that low-energy quantum states of squeezed light outperform classical sources for non-invasive bacteria detection in a sample.
Though tested on E. Coli, this technique applies to any bacterial species, promising significant potential for early detection and identification of bacteria.

In target detection, our microwave quantum illumination experiment successfully detected a short-range reflective target using quantum microwaves in a room-temperature environment,
proving that entangled microwaves can enhance target detection. This technology could be beneficial for short-range uses, though the feasibility of a long-range prototype remains to be seen
Our project culminated in significant advancements, pushing beyond existing boundaries in quantum information science.

Theoretically, we made substantial progress in quantum hypothesis testing and quantum sensing, enhancing our understanding of the potential
and limitations of quantum channel discrimination. This fundamental knowledge underpins quantum technological protocols,
including quantum reading and quantum illumination. We also extended this theory, formulating advanced protocols for quantum-enhanced decoding of barcodes and image classification.

From an experimental standpoint, we effectively transformed our theoretical concepts into tangible outcomes in the lab. Through various experiments, we demonstrated the superiority of quantum sources in retrieving information from physical systems.
We showcased the use of quantum properties like entanglement to improve data retrieval from optical memory prototypes, particularly under energy-constrained conditions.
Additionally, we highlighted quantum advantages in detecting and classifying delicate bacteria samples and scanning low-reflectivity targets in high-noise settings.

The project's completion unveils long-term impacts with socio-economic and societal implications:

1. Quantum Data Reading: Our approach to efficient data reading with minimal photons could spark the development of new organic memory technologies and photodegradable materials.
Particularly useful at high frequencies, these advancements could improve data storage and retrieval.

2. Quantum Pattern Recognition and Bio-probing: We laid the groundwork for non-invasive techniques to probe sensitive biological samples or human tissues.
This could enable earlier identification of patterns associated with bacterial growth, improving diagnoses and patient outcomes, thus potentially driving innovations in non-invasive biomedical imaging.

3. Quantum Radar/Scanner: Our development of a short-range quantum radar could lead to new types of environmental scanning. Its long-term applications may include obstacle detection and surveillance
in high-traffic areas, contributing to enhanced public safety and security.
scanner.jpg