Stefania Sciara



I am so grateful that my research work has been truly appreciated and recognized by a committee that may not be familiar with my topic. It shows that my doctoral work can be of high interest and acknowledged by a broader scientific community whose expertise is not strictly limited to quantum optics.

Stefania Sciara
Ph.D. Energy and et material sciences, 2020

Centre Énergie Matériaux Télécommunications | Supervisor: Roberto Morandotti

What brought you to INRS? What do you take away from your experience?

When I joined Prof. Morandotti’s group at INRS in 2016, the team was looking for a PhD student with expertise on theoretical quantum optics. I decided to apply and then obtained the position. Since the beginning, I was extremely excited by the idea of pursuing my doctoral studies in such a unique research institute as INRS, ranked indeed the first in research intensity both in Quebec and in Canada. What has also brought me to INRS was the one-of-a-kind opportunity to do research in quantum optics in such a renowned research institute together with Prof. Morandotti’s group, in such a way to combine my theoretical expertise and studies with the experimental skills of the team. The possibility of introducing theoretical quantum optics at INRS has also brought me here, since I saw huge potentials and advantages both for me and for the institute in terms of advancement in quantum research.

After four years of PhD, I am immensely grateful for having the opportunity to study in such a unique institute as INRS, not only because of its research level, but also thanks to the great experience that I have had, such as meeting excellent people (e.g., during lectures, seminars, etc.), participating in many interesting activities organized by the institute, as well as collaborating both in person and remotely with excellent physicists and scientists. The experience here at INRS has contributed significantly to my scientific and cultural skills, but also to my personal life. This is what I have really taken away from INRS.

Can you describe the issue and the impact of the research presented in your doctoral thesis?

My PhD studies have been focused on the theoretical investigation of complex entangled quantum states of light (photons), which feature a high number of physical units and/or dimensionality.

The motivation behind my research is the crucial role that quantum mechanics and entanglement play for both a better understanding of fundamental physics (as allowing for a comprehensive description of microscopic systems and their interactions), and for applied science (as potentially allowing us to solve issues associated with currently available technologies). For example, quantum mechanics and entanglement can enable faster and more powerful computing and information processing, as well as can guarantee unbreakable secure communications and advanced sensing and imaging. These tasks crucially require the use of complex entangled states. For this reason, a lot of effort has been spent towards the experimental realization of these states over the last few decades. However, realizing complex states in practical, scalable, and low-cost platforms, as demanded by modern technology, is a big milestone to achieve.

Moreover, a full exploitation of entanglement for applied science necessitates a deep understanding of this phenomenon, as well as a complete characterization of complex entangled states, which still represents an open issue in the scientific community.

This context has been the frame of my research lines, which have aimed at addressing these issues and challenges. To this end, leveraging the experiments on fundamental quantum optics performed by my research team through the use of integrated and fiber-based devices, I have focused my studies on the theoretical, yet experimentally oriented, investigation and characterization of entanglement of complex photon states.

I reported my research findings in the PhD thesis “Investigation, realization, and entanglement characterization of complex optical quantum states.” At its core is the theoretical development of quantum operators (specifically, ‘experimentally-friendly’ entanglement witnesses) enabling the detection and entanglement characterization of any arbitrarily complex quantum state by means of measurements that can be easily implemented and reproduced in the practice. These witness operators own the unique advantage of providing a good trade-off between the complexity of the measurement setting required for their detection and their tolerance towards white noise. I specifically focused on white noise because this is one of the most common noises in practical scenarios, as it is typically induced, for example, by losses and measurement inaccuracies, which can never be avoided in a laboratory.

Furthermore, being aware of these issues, I have derived an approach to customize the witness operators towards realistic practical scenarios, such as experimental restrictions and available measurement settings. While I have provided specific customized witnesses relying on the (fiber-based) optical components available in my lab for photon state manipulation, the approach that I have developed can be applied to any quantum state and experimental restriction.

I think that my doctoral research gives a significant contribution to theoretical, experimentally oriented, quantum optics. It introduces indeed new approaches for the measurement of complex photon states, by demonstrating that the characterization of these systems can still be a reasonable task. This result is of high interest and importance both for the scientific community (especially for quantum optics) and for quantum technology applications. In particular, the implementation of feasible techniques for the measurement of complex quantum states has always been a crucial, yet very challenging, milestone to achieve, as well as an open question since decades. Besides that, the results shown in my thesis can contribute to boost the use of quantum photonics for accessible avant-garde technologies, the broad use of which critically depends on their practicability and feasibility.

What does winning this award mean to you?

Receiving such a prestigious prize really means a lot to me. I am so grateful that my research work has been truly appreciated and recognized by a committee that may not be familiar with my topic. It shows that my doctoral work can be of high interest and acknowledged by a broader scientific community whose expertise is not strictly limited to quantum optics. I am aware that my research topic can be complex to understand, since it deals with non-trivial concepts, such as quantum mechanics, entanglement, complex photon states and quantum operators. For this reason, I have structured my thesis in such a way to give the reader a comprehensive introduction to these concepts, by constantly accompanying them with the motivation that has led me to the pursued research direction. Winning this award means that I have succeeded in transmitting the message that the content and results of my thesis can be relevant not only for a better understanding of fundamental physics and quantum optics, but also for their applications in mass affordable technologies. 

What’s the next chapter for you now that you graduate?

After my graduation, I have been pursuing my research at INRS as a postdoctoral fellow with Prof. Morandotti. While I mainly focused my PhD studies on fundamental theoretical, experimentally oriented, quantum optics, I now aim to take these findings to practical applications, with the goal of bringing quantum optics and photonics out of the lab, for example, for quantum secure communications, quantum state teleportation, and quantum computing. My main target is to contribute to make photon-based quantum technologies, which seem to be so inaccessible and unreachable to most, achievable to a broad audience, in a similar manner as all of us can possess and use laptops, personal computers, smartphones, and other similar devices. I truly think indeed that quantum photonics is the basis for next-generation technology, and I want my research to contribute to such an important milestone.

 Meet other awardees