If you have ever asked a quantum researcher about their subject, you will have realised that our first response is to tell you that the quantum world is weird, spooky, and counter-intuitive. It cannot be explained easily because we only just about understand it ourselves! After a bit more conversation, you’ll find us telling you that all these weird features are actually very useful: we talk about a potential for new technologies that can harness the quantum, from quantum computers to cryptography. The idea is to treat these quantum features as useful resources that help us to do things in an improved way. To do this, we need to carefully construct a framework that allows us to rigorously characterise these resources. Such a framework is called a quantum resource theory.
In this post, I will give a short explanation of resource theories. We begin by outlining the concept generally, but then focus on two particular examples of resources. The first example considers the resource of money in a fictional bank account, while the second example moves properly into the quantum world with the familiar resource of quantum entanglement.
Quantum states can exhibit bizarre but powerful properties, such as being in a superposition or containing correlations not possible in classical physics. If these properties can be controlled, then they can be exploited in quantum technologies to dramatically transform computing, enable secure cryptography, and unlock new ways of observing the universe. Quantum optics is a particularly fertile field for testing and developing these technologies – but how exactly can we design a quantum optics experiment to produce useful quantum states of light that can be put to good use? The usual methods involve painstaking calculations, clever insights, and utilising knowledge built up from years of experience and careful reading of previous researchers’ work. But the counter-intuitive nature of the quantum world, whilst enabling disruptive new technologies, can make it particularly challenging to design quantum experiments that can engineer useful states – our usual intuitions can fail us here. Indeed, while the current techniques used by researchers have led to a host of impressive and exciting results, we are far from finding the optimal methods to manipulate and control quantum states.
Happy 2017 from the Quanta Rei team! We close the current year with a guest post from our former member, long-time friend and collaborator Dr Rosario Lo Franco |RLF>
From the dawn of agriculture until the industrial revolution, all over the world, human beings have been facing the problem of food preservation. We are now quite familiar with many techniques, most of which utilised in our own kitchens, to reach this fundamental goal for our existence on Earth. Efficient and very employed procedures are, for instance: drying, salting, smoking, cooling and freezing. Let us focus on the last one, which works well for a very wide variety of foods. We are aware that, in order to preserve foods for long times by freezing, our freezers and refrigerators must be able to maintain temperatures well under zero Celsius degrees, typically −18° C or below (0° Fahrenheit or below). Air at the poles of our planet would be an extremely efficient freezer for foods, although it is not a very pleasant environment where to live (the average temperatures at North Pole and South Pole are, respectively: 0° C (32° F) and −28.2° C (−18° F) during summer; −40° C (−40° F) and −60° C (−76° F) during winter). There is therefore a continuous technological development in engineering efficient and eco-friendly freezing machines to assure a trustable and lasting food preservation. If someone comes and tells us that it is possible to preserve food by freezing at room temperature we wold not believe them, unless we are in front of Marvel’s Iceman (see picture aside).
Few people might have heard about Frederic Tudor before, but sometime in the early 1800s this Bostonian whiz kid had an idea that changed the world for ever. As most life-changing ideas, this was simple, groundbreaking, and completely crazy.
When young Tudor visited the West Indies for the first time, he was delighted by the warm Caribbean weather. He may have been sunbathing or walking on the beach when the idea struck him like a lightning. It was a new business model, completely overlooked, and extremely profitable: Why not cut ice in Boston, ship it to the tropics and sell it to local restaurants? They could start selling chilled drinks, or even ice-cream. Most people there had never seen ice before. They would go crazy about it!
I can imagine young Tudor considering with excitement the feasibility of his idea. Ice was free. At least in Boston. And there was plenty. One only needed to cut it in blocks. Ships were affordable at the time and, to keep the ice from melting, one could insulate it with sawdust, which was also essentially free. Believe it or not, nobody had thought about large scale commercial ice ventures before. Back then, ice was only used in small quantities wherever it was naturally available. But the idea of getting people to actually pay for ice was simply revolutionary.
One of the things I like most of my academic job is the opportunity to visit different places and interact with different communities. Already during my PhD at the University of Salerno, Italy, we had substantial funding to travel for workshops and conferences, and I exploited the opportunity as best as I could.. undoubtedly this helped me to promote my work and acquire networking skills that have played an important role in the development of my career. Today, I strongly encourage my students to do the same, and they are always happy to visit exotic locations for the sake of science. Moreover, we are ourselves, as a research group, creating such opportunities for a broader community of early career researchers. The most concrete example is the Quantum Roundabout postgraduate conference, which has become a tradition in Nottingham organised by my most junior students every other year. We are about to host the third edition on July 6th-8th, and I very much look forward to the scientific presentations and ideas exchange; Rosanna, Bartosz and Pietro are working so hard to make this a memorable event.
This week I am away attending a different type of event, at least different compared to my usual scientific conferences. I have been honoured as Young Scientist by the World Economic Forum (WEF), which means I have been selected within a group of 45 scientists under 40 years of age, including a delegation of European Research Council (ERC) Grantees, to attend the 10th edition of the WEF Annual Meeting of the New Champions in Tianjin (China), also known as Summer Davos 2016. This events brings together our (relatively small) group of scientists, a group of Tech Pioneers (promising entrepreneurs at the initial stages of their ventures), a large number of companies, press, and financial delegates, and world leaders including the Chinese Premier, the Canadian Minister of Innovation, etc., for a total of over 2000 participants. In a beautifully designed Convention Centre, we have all sorts of sessions from 7.30am to 6pm to learn and discuss around the main theme: The Fourth Industrial Revolution and its Transformational Impact.
So what is this all about?
What is reality? Is there a mathematically rigorous way to define it? Following the German philosopher Immanuel Kant, we can at least start by vaguely identifying two different kinds of reality: anything that we come across a posteriori as a result of an observation, so-called phenomenon, and anything-in-itself a priori with respect to our observation, so-called noumenon. In the following we will be interested in the latter form of reality and ask the question: is it there even if we do not observe it? In other (Einstein’s) words: is the moon there when no one looks? Of course many other questions immediately follow, such as: how can we ever prove that there is no reality-in-itself if we are by definition not allowed to observe it? Can we resort to the phenomenon to prove the nonexistence of the noumenon?