New Measure with New Insights: Precise Characteration of Quantum Entanglement Transformation
Professor Kun Fang from SDS collaborated with Dr. Thomas Theurer and Professor Gilad Gour from the University of Calgary to publish a paper titled "Single-shot entanglement manipulation of states and channels revisited". This work has been formally accepted and presented at QIP 2024, the most influential international conference on quantum information.
Quantum information science is an interdisciplinary field that integrates quantum physics, mathematics, and computer science. It represents a new paradigm for realizing various tasks such as computation, communication, and sensing based on the principles of quantum mechanics. By harnessing quantum resources such as superposition, entanglement, and interference, the capabilities of computation and communication can be significantly enhanced, holding the promise of overcoming classical technological bottlenecks in various industries, such as pharmaceutical research, new energy design, financial technology, and information security, thereby generating broad application value. However, to translate the theoretical advantages of quantum technology into practical applications, a thorough understanding of the capabilities and limitations of the quantum resources is of great importance, along with their appropriate application to specific problems.
Quantum resources, analogous to oil for a car, are at the core of driving quantum advantages. However, these quantum resources are highly fragile in practical situations and extremely sensitive to external noise. Noisy quantum resources have become a major barrier to the practical implementation of quantum technology. To address this issue, researchers have proposed techniques such as resource purification (or distillation). The essence of this technique lies in transforming a large amount of noisy resource into a smaller amount of pure resource, just like reducing a dilute solution to a concentrated one.
More specifically, the goal is to transform n copies of a noisy quantum state into m copies of pure resource. Typically m is much smaller than n. Regarding to this transformation, there are a few key questions to explore. For instance, if we want to obtain a fix amount of the target resource, how much noisy resources need to concentrate? Conversely, if we have fixed amount of the noisy resource, how much pure resource we obtain at most?
In collaboration with Dr. Thomas Theurer and Professor Gilad Gour from the University of Calgary, Professor Kun Fang from SDS, recently provided precise answers to these problems, in their paper titled "Single-shot entanglement manipulation of states and channels revisited." This work has been formally accepted and presented at QIP 2024, the most influential international conference on quantum information. It introduces a novel metric for quantifying errors in quantum entanglement state transformations and offers analytical formulas and precise characterizations through second-order estimations of quantum information entropy. This work fully demonstrates that the same problem exhibits vastly different behaviors under different error metrics. Therefore, by redesigning error measures, seemingly complex problems can be greatly simplified, leading to more accurate and in-depth analyses of the original problems. This approach is expected to be further extended to the analysis of other key quantum resources, helping to improve the efficiency of quantum resource utilization in various scenarios, overcome noise bottlenecks, and thereby accelerate the practical implementation of quantum advantage.