Luca Vannucci

Project title

Indistinguishable single-photon emission for quantum technologies from transition metal dichalcogenides (INSPEQT)

What is your project about?

This project deals with an essential hardware component of a quantum computers. One possible way to build a quantum computer is to use photons as quantum bits and make them interfere to perform operations. The photons must be exactly identical to each other in order to interfere successfully, and when this condition is fulfilled, they are said to be “indistinguishable”. 

In this project, we will develop new theoretical models and experimental methods to obtain indistinguishable photons from a special class of ultra-thin materials called “transition metal dichalcogenides”, with a thickness of only few atomic layers.

How did you become interested in your particular field of research?

My general interest in physics is probably genetic, as I share it with both my parents. The specific interest in photons and their interaction with matter originates from my PhD time, when I was working with quantum interference of fundamental quantum objects such as electrons and photons.
I am fascinated by the subtle and counter-intuitive phenomena of the quantum world.

What are the scientific challenges and perspectives in your project?

An optical computer will function correctly only if all the qubits (i.e. photons) are exactly identical to each other. However, when working with a solid-state hardware, it is very difficult to obtain identical photons every single time due to unavoidable noise. For example, some of the energy that is stored in the device may be lost into vibrations of the crystalline lattice, thereby reducing the energy of the photon.

Another challenging task is to initialize the emitter correctly. Any emitter is somewhat similar to an atom: if the atom is excited, it relaxes to a state with lower energy by emitting a photon. While the process of spontaneous emission is very well understood, it is quite challenging to prepare the emitter in the required excited state with a fast and reliable process.

What is your estimate of the impact, which your project may have to society in the long term?

Thanks to the superposition principle, a computer that uses the laws of quantum mechanics will be able to perform calculations that are impossible for even the most powerful computer in the world. 

For example, a quantum computer could simulate the complex reaction mechanism that is needed to produce ammonia (the most important fertilizer in the world) or predict how certain molecules combine together to make new drugs. This is why big companies such as Google, IBM, and Microsoft are striving to realize a fully-functioning quantum computer.
In this context, my project will improve the understanding of one of its essential components.

Which impact do you expect the Sapere Aude programme will have on your career as a researcher?

I am delighted to receive this prestigious grant from DFF, and I consider this an important professional achievement and a huge opportunity. It will give me full freedom to pursue my research objectives and explore fascinating phenomena. Thanks to the Sapere Aude programme, I will have the opportunity to establish and lead my own team composed by a PhD student, a PostDoc, and myself, and to collaborate with other excellent researchers both in Denmark and abroad.

Background and personal life

I was born in Genoa, Italy, where I also went to school and did my studies in Physics. I spend most of my free time together with my partner and our 2-year old daughter. The rest I devote to reading books, listening to podcasts (well-explained, possibly), and cycling around Sjælland.