ETH Zurich researchers have succeeded in demonstrating that quantum mechanical objects that are far apart can be much more strongly correlated with each other than is possible in conventional systems. For this experiment, they used superconducting circuits for the first time.
A novel protocol for quantum computers could reproduce the complex dynamics of quantum materials.
RIKEN researchers have created a hybrid quantum-computational algorithm that can efficiently calculate atomic-level interactions in complex materials. This innovation enables the use of smaller quantum computers or conventional ones to study condensed-matter physics and quantum chemistry, paving the way for new discoveries in these fields.
A quantum-computational algorithm that could be used to efficiently and accurately calculate atomic-level interactions in complex materials has been developed by RIKEN researchers. It has the potential to bring an unprecedented level of understanding to condensed-matter physics and quantum chemistry—an application of quantum computers first proposed by the brilliant physicist Richard Feynman in 1981.
It could be a strange way of achieving immortality—or at least, everlasting life for copies of you.
Researchers prove the fully nonclassical nature of a three-party quantum network, a requirement for developing secure quantum communication technologies.
Graphene’s valence and conduction bands meet at a point, making the single-layer crystal a semimetal. Researchers have predicted that spin-orbit coupling of carbon’s outer electrons opens a narrow gap between these bands—but only for the crystal’s bulk. Along the edges, spin-dependent states bridge the band gap, allowing the resistance-free flow of electrons: a quantum spin Hall effect. The weakness of carbon’s spin-orbit coupling means that this quantum spin Hall effect is too fragile to observe, however. Now Pantelis Bampoulis of the University of Twente in the Netherlands and his collaborators have seen the quantum spin Hall effect in graphene’s germanium (Ge) analog, germanene [1]. Furthermore, they show that germanene’s structure—a honeycomb like graphene’s, but lightly buckled—allows the quantum spin Hall effect to be turned off and on using an electric field.
Bampoulis and his collaborators grew a germanene monolayer on a buffer layer of Ge atop a substrate of Ge2Pt. Using a scanning tunneling microscope, they discriminated between the edge and the bulk states of germanene and measured how current depended on voltage under an external electric field perpendicular to the layer. At low field strengths, germanene exhibited a robust quantum spin Hall effect due to germanium’s strong spin-orbit coupling. At high field strengths, the edge states no longer bridged the gap and germanene became a normal insulator. But at a critical intermediate value, germanene underwent a topological phase transition as the otherwise separated conduction and valence bands in the bulk came together and the symmetry that sustained the quantum spin Hall effect was destroyed.
The robustness of germanene’s quantum spin Hall effect and the fact that it can be turned off with an applied electric field suggest that the material could be used to make room-temperature topological field-effect transistors.
The University of Illinois Urbana-Champaign’s nuclear physics group is participating in the nEDM experiment at Oak Ridge National Laboratory, aiming to measure the neutron’s electric dipole moment to constrain theories in particle physics. The researchers aim to construct sensors for the nEDM experiment and explore their potential applications in quantum information science. The unique quantum properties of nitrogen-vacancy diamond make it a promising candidate for quantum sensing and quantum memory.
The nuclear physics group at the University of Illinois Urbana-Champaign is looking for evidence of new physics in neutrons, electrically neutral particles that hold atomic nuclei together with an interaction called the strong force. Faculty and researchers are participating in the nEDM experiment at Oak Ridge National Laboratory which will measure the neutron’s electric dipole moment, a property that allows neutrons to interact with electric fields despite their neutrality. A precise measurement will constrain theories extending the current standard model of particle physics. To achieve this, the researchers must accurately measure subtle changes in very strong electric fields.
Professor of Physics Douglas Beck has been awarded a grant from the Department of Energy to develop sensors based on nitrogen-vacancy diamond, a material whose quantum properties at low temperatures make it unusually sensitive to electric fields. His research group has shown that the material can measure strong electric fields, and the award will allow the researchers to construct sensors ready to use in the nEDM experiment. In addition, the material’s quantum properties make it a promising candidate for quantum information science. The researchers will also explore these potential applications.
How can Marvel movie character Ant-Man produce such strong energy out of his small body? The secret lies in the transistors on his suit that amplify weak signals for processing. Transistors that amplify electrical signals in the conventional way lose heat energy and limit the speed of signal transfer, which degrades performance. What if it were possible to overcome such limitations and make a high-performance suit that is light and small but without the loss of heat energy?
A POSTECH team of Professor Kyoung-Duck Park and Yeonjeong Koo from the Department of Physics and a team from ITMO University in Russia led by Professor Vasily Kravtsov jointly developed a nano-excitonic transistor using intralayer and interlayer excitons in heterostructure-based semiconductors, which addresses the limitations of existing transistors. The research was recently published in the journal ACS Nano.
Excitons are responsible for light emission of semiconductor materials and are key to developing a next-generation light-emitting element with less heat generation and a light source for quantum information technology due to the free conversion between light and material in their electrically neutral states.
Ragsxl/Wikimedia Commons.
Unlike classical computers, which operate on binary bits (0 and 1), quantum computers operate on quantum bits or qubits. Qubits can exist in a state of superposition. This means that any qubit has some probability of existing simultaneously in the 0 and 1 states, exponentially increasing the computational power of quantum computers.
Meeting the world’s energy demands is reaching a critical point. Powering the technological age has caused issues globally. It is increasingly important to create superconductors that can operate at ambient pressure and temperature. This would go a long way toward solving the energy crisis.
Advancements with superconductivity hinge on advances in quantum materials. When electrons inside of quantum materials undergo a phase transition, the electrons can form intricate patterns, such as fractals. A fractal is a never-ending pattern. When zooming in on a fractal, the image looks the same. Commonly seen fractals can be a tree or frost on a windowpane in winter. Fractals can form in two dimensions, like the frost on a window, or in three-dimensional space like the limbs of a tree.
Dr. Erica Carlson, a 150th Anniversary Professor of Physics and Astronomy at Purdue University, led a team that developed theoretical techniques for characterizing the fractal shapes that these electrons make, in order to uncover the underlying physics driving the patterns.
In a development that could make quantum computers less prone to errors, a team of physicists from Quantinuum, California Institute of Technology and Harvard University has created a signature of non-Abelian anyons (nonabelions) in a special type of quantum computer. The team has published their results on the arXiv preprint server.
As scientists work to design and build a truly useful quantum computer, one of the difficulties is trying to account for errors that creep in. In this new effort, the researchers have looked to anyons for help.
Anyons are quasiparticles that exist in two dimensions. They are not true particles, but instead exist as vibrations that act like particles—certain groups of them are called nonabelions. Prior research has found that nonabelions have a unique and useful property—they remember some of their own history. This property makes them potentially useful for creating less error-prone quantum computers. But creating, manipulating and doing useful things with them in a quantum computer is challenging. In this new work, the team have come close by creating a physical simulation of nonabelions in action.
