Quantum gates require controlled interactions between different degrees of freedom. A tunable coupling has now been demonstrated between the phonon modes of a mechanical resonator designed for storing and manipulating quantum information.
It wasn’t until Albert Einstein that we developed a more sophisticated mathematical understanding of time and space that allowed physicists to probe deeper into the connections between them. In their endeavors, physicists also discovered that seeking the origin of time forces us to confront the origins of the universe itself.
What exactly is time, and how did it come into being? Did the dimension of time exist from the moment of the Big Bang, or did time emerge as the universe evolved? Recent theories about the quantum nature of gravity provide some unique and fantastic answers to these millennia-old questions.
An experiment carried out in Italy, backed by theoretical support from Newcastle University, has produced the first experimental evidence of vacuum decay.
In quantum field theory, when a not-so-stable state transforms into the true stable state, it’s called “false vacuum decay.” This happens through the creation of small localized bubbles. While existing theoretical work can predict how often this bubble formation occurs, there hasn’t been much experimental evidence. Now, an international research team involving Newcastle University scientists has for the first observed these bubbles forming in carefully controlled atomic systems. Published in the journal Nature Physics, the findings offer experimental evidence of bubble formation through false vacuum decay in a quantum system.
Researchers have developed a new spectroscopy method to study ultrafast processes in strongly correlated materials, achieving sub-femtosecond resolution.
An international team of researchers from the European XFEL together with colleagues from the Max Born Institute in Berlin, the Universities of Berlin and Hamburg, The University of Tokyo, the Japanese National Institute of Advanced Industrial Science and Technology (AIST), the Dutch Radboud University, Imperial College London, and Hamburg Center for Ultrafast Imaging, have presented new ideas for ultrafast multi-dimensional spectroscopy of strongly correlated solids. This work will be published today (January 24) in Nature Photonics.
Exploring Strongly Correlated Solids
Tunneling is one of most fundamental processes in quantum mechanics, where the wave packet could traverse a classically insurmountable energy barrier with a certain probability.
On the atomic scale, tunneling effects play an important role in molecular biology, such as accelerating enzyme catalysis, prompting spontaneous mutations in DNA and triggering olfactory signaling cascades.
Photoelectron tunneling is a key process in light-induced chemical reactions, charge and energy transfer and radiation emission. The size of optoelectronic chips and other devices has been close to the sub-nanometer atomic scale, and the quantum tunneling effects between different channels would be significantly enhanced.
Certain materials have desirable properties that are hidden, and just as you would use a flashlight to see in the dark, scientists can use light to uncover these properties.
Researchers at the University of California San Diego have used an advanced optical technique to learn more about a quantum material called Ta2NiSe5 (TNS). Their work appears in Nature Materials.
Materials can be perturbed through different external stimuli, often with changes in temperature or pressure; however, because light is the fastest thing in the universe, materials will respond very quickly to optical stimuli, revealing properties that would otherwise remain hidden.
Add a dash of creamer to your morning coffee, and clouds of white liquid will swirl around your cup. But give it a few seconds, and those swirls will disappear, leaving you with an ordinary mug of brown liquid.
Something similar happens in quantum computer chips—devices that tap into the strange properties of the universe at its smallest scales—where information can quickly jumble up, limiting the memory capabilities of these tools.
That doesn’t have to be the case, said Rahul Nandkishore, associate professor of physics at the University of Colorado Boulder.
Year 2019 This proves that we may have infinite worlds and infinite possibilities.
Historically, correspondence rules and quantum quasi-distributions were motivated by classical mechanics as a guide for obtaining quantum operators and quantum corrections to classical results. In this paper, we start with quantum mechanics and show how to derive the infinite number of quantum quasi-distributions and corresponding c-functions. An interesting aspect of our approach is that it shows how the c-numbers of position and momentum arise from the quantum operator.
A radical theory that consistently unifies gravity and quantum mechanics while preserving Einstein’s classical concept of spacetime is announced today in two papers published simultaneously by UCL (University College London) physicists.
Modern physics is founded upon two pillars: quantum theory on the one hand, which governs the smallest particles in the universe, and Einstein’s theory of general relativity on the other, which explains gravity through the bending of spacetime. But these two theories are in contradiction with each other and a reconciliation has remained elusive for over a century.
The prevailing assumption has been that Einstein’s theory of gravity must be modified, or “quantised”, in order to fit within quantum theory. This is the approach of two leading candidates for a quantum theory of gravity, string theory and loop quantum gravity.
The use of NISQ devices for useful quantum simulations of materials and chemistry is still mainly limited by the necessary circuit depth. Here, the authors propose to combine classically-generated effective Hamiltonians, hybrid fermion-to-qubit mapping and circuit optimisations to bring this requirement closer to experimental feasibility.
