International Conference on Condensed Matter Physics

  A density wave (DW) is a fundamental type of long-range order in quantum matter tied to self-organization into a crystalline structure. Although density waves are seen in a wide range of materials, such as metals, insulators, and superconductors, studying them has proven challenging, particularly when this order (the patterns of the wave’s particles) coexists with other types of organization, such as superfluidity, which allows particles to flow without resistance. Scientists at EPFL have found a new way to create a “density wave” in an atomic gas. The findings could lead to a better understanding of the behavior of quantum matter. Professor Jean-Philippe Brantut at EPFL said, “Cold atomic gases were well known in the past for the ability to ‘program’ the interactions between atoms. Our experiment doubles this ability!” To study this interaction, Brantut, and his colleagues created a “unitary Fermi gas,” a thin gas of lithium atoms that has been cooled to incredibly low temperatures

The surprising prediction that currents can flow forever in small normal metal rings was confirmed almost twenty years ago. Highly precise new experiments find good agreement with theory that was not seen till now. Figure 1: (Top) This is an artist’s concept, adapted from Ref. [15], showing part of the SQUID assembly—the field and pickup loops hovering over the gold rings of the sample. (Bottom) This figure (Fig. 3(a) from Ref. [9]) presents the difference between the averaged nonlinear responses, induced by the flux and measured by the SQUID, of two rings with sizeable responses, at a range of temperatures vs the applied external flux. Multiple data sets for some temperatures attest to the reproducibility of the results. An approximately fitted sinusoidal curve yields a period which is close to h/eℎ/� It is well known that in a superconductor electrons react strongly to a magnetic field, creating currents that try to shield the flux in the bulk case (the Meissner effect) or cause the

  In recent years, physicists have been trying to attain the control of chemical reactions in the quantum degenerate regime, where de Broglie wavelength of particles becomes comparable to the spacing between them. Theoretical predictions suggest that many-body reactions between bosonic reactants in this regime will be marked by quantum coherence and Bose enhancement, yet this has been difficult to validate experimentally. Researchers at University of Chicago recently set out to observe these elusive many-body chemical reactions in the quantum degenerate regime. Their paper, published in Nature Physics, presents the observation of coherent, collective reactions between Bose-condensed atoms and molecules. "The quantum control of molecular reactions is a fast-progressing research area in atomic and molecular physics," Cheng Chin, one of the researchers who carried out the study, told Phys.org. "People envision applications of cold molecules in precision metrology, quantum i

  This is the first time a highly ordered crystal of bosonic particles called excitons has been created in a real — as opposed to synthetic — matter system. Subatomic particles come in one of two broad types: fermions and bosons. One of the biggest distinctions is in their behavior. Bosons can occupy the same energy level; fermions don’t like to stay together. Together, these behaviors construct the Universe as we know it.. Fermions, such as electrons, underlie the matter with which we are most familiar as they are stable and interact through the electrostatic force. Meanwhile bosons, such as photons, tend to be more difficult to create or manipulate as they are either fleeting or do not interact with each other. “A clue to their distinct behaviors is in their different quantum mechanical characteristics,” said first author Richen Xiong, a graduate student at the University of California at Santa Barbara. “Fermions have half-integer spins such as 1/2 or 3/2 etc., while bosons have whol

For decades, scientists sought a way to apply the outstanding analytical capabilities of neutrons to materials under pressures approaching those surrounding the Earth's core. These extreme pressures can rearrange a material's atoms, potentially resulting in interesting new properties Be an ACS Industry Insider Sign-up and get free, monthly access to articles that cover exciting, cutting edge discoveries in Energy, Environmental Science and Agriculture A breakthrough resulted in 2022 when researchers at Oak Ridge National Laboratory's Spallation Neutron Source squeezed a tiny sample of material—sandwiched between two diamonds—to a record 1.2 million times the average air pressure at sea level, or approximately 1.2 megabar. But this was only the start—they still had to produce useful data from the experiments. Now those same scientists have implemented software that removes the signal interference affecting the neutrons as they pass through the diamonds before reaching the sa

Of all the science-fiction-sounding names that have come to fruition in recent years, perhaps none is as mysterious or seemingly fictitious as time crystals. The name evokes something between Back to the Future and Donnie Darko, and the reality is perhaps crazier than either. Two separate groups of scientists recently reported they observed time crystals, which lends credence to the idea that this theoretical state of matter is something humans can actually create and observe. And indeed, time crystals can be grown in a child’s bedroom. But, it requires nuclear sensors and lasers to help time crystals reach their full potential and then measure and observe them. This combination of dramatic scientific terms and shockingly simple objects is a great analogy for time crystals as a whole. Read on to understand what they are and how they might affect our lives.   What Are Time Crystals? Time crystals are systems of atoms that arrange themselves in time the way more traditional solids crysta

At super-low temperatures, a crystal called samarium hexaboride behaves in an unexplained, imagination-stretching way. Interactions between electrons inside samarium hexaboride appear to be giving rise to an exotic quantum behavior new to researchers. In a deceptively drab black crystal, physicists have stumbled upon a baffling behavior, one that appears to blur the line between the properties of metals, in which electrons flow freely, and those of insulators, in which electrons are effectively stuck in place. The crystal exhibits hallmarks of both simultaneously. “This is a big shock,” said Suchitra Sebastian, a condensed matter physicist at the University of Cambridge whose findings appeared today in an advance online edition of the journal Science. Insulators and metals are essentially opposites, she said. “But somehow, it’s a material that’s both. It’s contrary to everything that we know.” The material, a much-studied compound called samarium hexaboride or SmB6, is an insulator at

  Defects often limit the performance of devices such as light-emitting diodes (LEDs). The mechanisms by which defects annihilate charge carriers are well understood in materials that emit light at red or green wavelengths, but an explanation has been lacking for such loss in shorter-wavelength (blue or ultraviolet) emitters. Researchers in the Department of Materials at UC Santa Barbara, however, recently uncovered the crucial role of the Auger-Meitner effect, a mechanism that allows an electron to lose energy by kicking another electron up to a higher-energy state. "It is well known that defects or impurities—collectively referred to as 'traps'—reduce the efficiency of LEDs and other electronic devices," said Materials Professor Chris Van de Walle, whose group performed the research. The new methodology revealed that the trap-assisted Auger-Meitner effect can produce loss rates that are orders of magnitude greater than those caused by other previously considered mec

  Electromagnetic forces occur when an electromagnetic field interacts with electrically charged particles, such as those that make up a plasma (ie. electrons, protons and other ions). It include the electric force, which produces electric fields between charged forces, and the magnetic force, which manifests itself as magnetic fields wherever there are moving charges. Plasmas interact strongly with electromagnetic forces, resulting in complexity in structure and motion that far exceeds that found in gases, liquids, and solids. This is exemplified by solar flares and the solar wind, which overcome the Sun’s magnetic field, accelerates away, and out into interplanetary space. The formula that describe the behavior of electric and magnetic fields, and their interactions with matter, were derived by Oliver Heaviside (1831-1925), but are now called Maxwell’s equations after James Clerk Maxwell (1831–1879). Visit: https://condensed-matter.sfconferences.com/ Twitter: https://twitter.com/magn

  A team of physicists and geologists at CEA DAM-DIF and Universit´e Paris-Saclay, working with a colleague from ESRF, BP220, F-38043 Grenoble Cedex and another from the European Synchrotron Radiation Facility, has succeeded in synthesizing a single-crystalline iron in a form that iron has in the Earth's core. In their paper published in the journal Physical Review Letters, the group describes how they used an experimental approach to synthesize pure single-crystalline ε-iron and possible uses for the material In trying to understand Earth's internal composition, scientists have had to rely mostly on seismological data. Such studies have led scientists to believe that the core is solid and that it is surrounded by liquid. But questions have remained. For example, back in the 1980s, studies revealed that seismic waves travel faster through the Earth when traveling pole to pole versed equator to equator, and no one could explain why. Most theories have suggested it is likely beca

  A common metal paper clip will stick to a magnet. Scientists classify such iron-containing materials as ferromagnets. A little over a century ago, physicists Albert Einstein and Wander de Haas reported a surprising effect with a ferromagnet. If you suspend an iron cylinder from a wire and expose it to a magnetic field, it will start rotating if you simply reverse the direction of the magnetic field. "Einstein and de Haas's experiment is almost like a magic show," said Haidan Wen, a physicist in the Materials Science and X-ray Science divisions of the U.S. Department of Energy's (DOE) Argonne National Laboratory. "You can cause a cylinder to rotate without ever touching it." In Nature, a team of researchers from Argonne and other U.S. national laboratories and universities now report an analogous yet different effect in an "anti"-ferromagnet. This could have important applications in devices requiring ultra-precise and ultrafast motion control. On

The use of electric fields is a powerful approach to manipulate molecular electronic states, which can subsequently influence the optical properties, adsorption structures, oxidation states, vibrational frequencies, and chemical reactivity of molecules.​​​​​​​ A recent study published in the journal Advanced Materials focuses on developing a novel platform for studying the effects of electric fields on molecular electronic states using two-dimensional (2D) ferroelectric materials. This could be a major breakthrough in the field of molecular electronics and quantum science, as it offers a new way of influencing the quantum states of deposited molecules via the proximity effect. 2D Ferroelectric Materials 2D ferroelectric materials provide a promising platform for the electrical control of quantum states because of their unique combination of ferroelectric and quantum mechanical properties. Ferroelectricity refers to the ability of certain materials to have a spontaneous electric polariz