The most exciting area of physics research right now has to be the field of ‘quantum engineering’ – the exploitation of the laws of quantum mechanics to design and build devices with new and unprecedented properties. When I was a student, the mysterious and counter-intuitive properties of the quantum world fascinated and perplexed me. What did it mean to speak of a particle being in two places at once? Why should the physical world, on a tiny scale of atoms and molecules, turn out to behave in such an unreasonable way? And what use was it anyway?
- Learn more about quantum technology development in the video above
The first quantum physicists grappled with these questions around 100 years ago. In their pioneering experiments on the properties of very small things, they had to work with what nature provided. For example, they could study the light given off by different kinds of atom, but they could not change the properties of those atoms – all the hydrogen atoms in the universe as the same! It would have been a remote dream of those scientists to be able to manipulate the properties of an atom at will in order to test their theories. Yet, in the last 30 years, advances in micro- and nano-scale fabrication technology have allowed exactly that, and ‘artificial atoms’ with controllable properties are routinely used in research. It is now possible to design and engineer exquisitely precise devices which behave exactly as predicted by quantum theory. For example, scientists can make an electrical circuit containing the smallest possible ‘particle’ of microwave energy, and use that energy to change the state of an artificial atom in a perfectly controlled way.
- University of California physics and computer engineering Professor David Awschalom talks about electronics in the quantum age
Examples like this might seem like an abstract exercise in pure science, but in the emerging field of quantum engineering, the laws of quantum mechanics have become a practical tool to be exploited in new kinds of devices – with potential applications as diverse as faster computers, more accurate clocks, and gravity sensors for oil and gas exploration. For the quantum engineer, concepts such as ‘entanglement’ (two separate objects appearing as if they were invisibly linked together) are all in a day’s work and no more unusual than the properties of setting concrete are to a civil engineer designing a bridge. It seems that after 100 years, quantum mechanics has come of age and is poised to usher in revolutionary new technology.
One of the most intriguing ongoing searches (at least for me) is the gravitational wave (GW) detection efforts being done by LIGO collaboration. We already know about at least two black hole merger events. These guys are really interesting, since they serve as a good general relativity test. There are a bunch of other things that we can constraint with the statistics of these events... However, there are even more exciting things, that we can find with a GW telescope.
We still haven't seen any neutron-star with black hole or neutron star with neutron star mergers. That's a little weird, since there should be tons of them (according to predictions). It seems like these events are below the sensitivity limit.
Why these things will be exciting to catch? Because unlike black holes, neutron stars are made of matter, and this matter is in the most extreme conditions in our Universe, with overwhelmingly large magnetic fields, pressures and densities deep inside the core. The problem is that we still don't know what the neutron star interior looks like, what is it made of. It would be really nice to look deep inside, to somehow break the neutron star apart... And that's when merging processes come in.
When two neutron stars collide or when a neutron star falls into a black hole, during the very last seconds of this collision the neutron star squeezes and breaks apart, extracting an enormous amount of energy in the form of an electromagnetic radiation. If we're able to recognize this electromagnetic radiation (caught with some gamma-ray or x-ray telescope) just before the merging event, which will be signified by the GW telescope, we'll have a really good chance to find out what a neutron star is made of.