Latest news with #Caltech
Yahoo
8 hours ago
- General
- Yahoo
Physicists force atoms into state of quantum 'hyper-entanglement' using tweezers made of laser light
When you buy through links on our articles, Future and its syndication partners may earn a commission. Using optical tweezers composed of laser light, researchers have developed a novel way to manipulate individual atoms and create a state of hyper-entanglement. This breakthrough could lead to new forms of quantum computing and advances in quantum simulations designed to answer fundamental questions about physics. Caltech scientists have been using optical tweezers to control individual atoms for several decades, leading to a number of advances, including quantum error correction and a method for creating the world's most accurate clocks. One persistent issue in the process, however, has been the natural motion of atoms, which can introduce noise (and errors) into a quantum system. But in the breakthrough study, published in the journal Science, that weakness has been transformed. "We show that atomic motion, which is typically treated as a source of unwanted noise in quantum systems, can be turned into a strength," said Adam Shaw in a statement on Caltech's website, a postdoctoral researcher and first author on the study. Instead of a disruptive influence, Shaw and colleagues have harnessed that movement to create hyper-entangled sets of atoms. Hyper-entanglement is distinct from traditional quantum entanglement, which describes two or more particles that are in-sync and share a property across vast distances. Hyper-entangled atoms, by contrast, can share multiple properties at the same time. In the experiment, the Caltech team was able to link both the states of motion and electronic states (a measure of an atom's internal energy level) in a pair of atoms at the same time. Related: Physicists create hottest Schrödinger's cat ever in quantum technology breakthrough This achievement is an important step in terms of both volume and efficiency, according to Manuel Endres, a professor of physics at Caltech and co-lead author of the study. "This allows us to encode more quantum information per atom," he said in the statement. "You get more entanglement with fewer resources." To achieve that state of hyper-entanglement, the team first had to cool an alkaline earth atom with no charge using a novel method that Endres said involved "detection and subsequent active correction of thermal motional excitations." By deploying this method, the team was able to almost completely freeze the atom's motion. The next step was to cause atoms to oscillate like a pendulum on a tiny scale in two different directions simultaneously, creating a state of superposition — when a particle exhibits opposite properties at the same time. These oscillating atoms were then entangled with partners that matched their motion, and finally hyper-entangled to also mirror their electronic states. RELATED STORIES —Quantum computing: What is quantum error correction (QEC) and why is it so important? —Quantum 'miracle material' can store information in a single dimension thanks to newly discovered magnetic switching —Building quantum supercomputers: Scientists connect two quantum processors using existing fiber optic cables for the first time According to Endres, the point of the experiment was to find the limit of control they could exercise over the atoms. "We are essentially building a toolbox," he said. "We knew how to control the electrons within an atom, and we now learned how to control the external motion of the atom as a whole — it's like an atom toy that you have fully mastered." One of the most exciting facets of this discovery is the implication that even more states or properties could be entangled, which Endres said could lead to a number of potential applications. "Motional states could become a powerful resource for quantum technology, from computing to simulation to precision measurements."
RNZ News
18 hours ago
- General
- RNZ News
Possible new dwarf planet spotted near the edge of the solar system
By Will Dunham , Reuters An artist's impression of Planet Nine. Photo: Caltech Scientists have identified an object about 700km wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly elongated orbital path around the sun. The researchers called it one of the most distant visible objects in our solar system and said its existence indicates that a vast expanse of space beyond the outermost planet Neptune and a region called the Kuiper Belt may not be deserted, as long thought. The Kuiper Belt is populated by numerous icy bodies. Given the name 2017 OF201, the object falls into a category called trans-Neptunian objects that orbit the sun at a distance beyond that of Neptune. The object takes about 25,000 years to complete a single orbit of the sun, compared to 365 days for Earth to do so. The researchers said 2017 OF201 was identified in observations by telescopes in Chile and Hawaii spanning seven years. "It is potentially large enough to qualify as a dwarf planet. Its orbit is very wide and eccentric, which means it experienced an interesting orbital migration path in the past," said astrophysicist Sihao Cheng of the Institute for Advanced Study in Princeton, New Jersey, who led the study with collaborators Jiaxuan Li and Eritas Yang, graduate students at Princeton University. Its size is estimated to be a bit smaller than Ceres, which is the smallest of the solar system's five recognised dwarf planets and has a diameter of about 950km. Pluto, the largest of those dwarf planets, has a diameter of about 2377km. The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth's and 50 times smaller than Pluto's. "We don't know the shape yet. Unfortunately, it is too far away and it is a bit difficult to resolve it with telescopes," Cheng said. "Its composition is totally unknown yet, but likely similar to other icy bodies." The discovery was announced by the Minor Planet Center of the International Astronomical Union, an international organisation of astronomers, and detailed in a study posted on the open-access research site arXiv. The study has not yet been peer-reviewed. Earth's orbital distance from the sun is called an astronomical unit. 2017 OF201 is currently located at a distance of 90.5 astronomical units from the sun, meaning 90.5 times as far as Earth. But at its furthest point during its orbit, 2017 OF201 is more than 1,600 astronomical units from the sun, while the closest point on its orbit is about 45 astronomical units. That means it sometimes is closer to the sun than Pluto, whose orbital distance ranges from 30 to 49 astronomical units as it travels an elliptical path around the sun. The researchers suspect that the extreme orbit of 2017 OF201 may have been caused by a long-ago close encounter with the gravitational influence of a giant planet. "We still don't know much about the solar system far away because currently, it is difficult to directly see things beyond about 150 astronomical units," Cheng said. "The presence of this single object suggests that there could be another hundred or so other objects with similar orbit and size. They are just too far away to be detectable right now." The five dwarf planets recognised by the International Astronomical Union are, in order of distance from the sun: Ceres, which is the largest object in the asteroid belt between Mars and Jupiter, then Pluto, Haumea, Makemake and Eris, which all orbit beyond Neptune. The organisation defines a planet and a dwarf planet differently. A planet must orbit its host star - in our case the sun - and must be mostly round and sufficiently large that its gravitational strength clears away any other objects of similar size near its orbit. A dwarf planet must orbit the sun and be mostly round but it has not cleared its orbit of other objects. Cheng said the discovery of 2017 OF201 has implications for hypotheses involving the potential existence of a ninth planet in our solar system, dubbed Planet X or Planet Nine. This is because 2017 OF201's orbit does not follow the pattern exhibited by other known trans-Neptunian objects, which tend to cluster together. Some scientists had hypothesized that such clustering was caused by the gravity of a yet-to-be-discovered planet. -Reuters
San Francisco Chronicle
2 days ago
- Business
- San Francisco Chronicle
Here's how dependent each UC campus is on international students
With tens of thousands of students from other countries studying at University of California campuses, UC officials say they are 'very concerned' about President Donald Trump's targeting of international enrollment, which could put a dent in colleges' budgets, slow research and harm the state economy. On Thursday, Secretary of State Marco Rubio announced that the Trump administration will 'aggressively revoke visas for Chinese students.' Also this week, Trump paused new student visa interviews, and he dangled the idea of a 15% cap on international enrollment. About 41,000 international students study at UC's 10 campuses, about 13% of systemwide enrollment. Nearly a third of UC graduate students, 31%, are from another country, while 9% of undergraduates are from outside the U.S. China accounts for the greatest share of international students at UC by far — 43%. 'Our international students and scholars are vital members of our university community and contribute greatly to our research, teaching, patient care and public service mission,' the university said in a statement. Officials at major private universities in California expressed concern as well. At Stanford, where ratios of international students are similar to UC's, President Jonathan Levin said it was 'self-defeating to send away young people with so much potential to contribute to the country.' A spokesperson for Caltech, where international students include 14% of undergraduates and 47% of graduate students, credited 'foreign talent' with helping American innovators develop 'extraordinary new advances,' from AI, to smartphones, personal computing and sequencing the human genome. Trump's actions 'undermine the stability of our country's research, education and innovation enterprise, a system that has ensured U.S. leadership and global competitiveness in the advancement of science, the development of new technologies and the prosperity of our communities,' said Caltech spokesperson Shayna Chabner. The Trump administration's efforts to reduce the presence of international students is part of an 'America first' policy, Rubio said, adding that the restrictions will focus especially on students 'with connections to the Chinese Communist Party or studying in critical fields.' He did not say how the administration would determine which students have connections with the Chinese government or what fields are considered critical. But the crackdown is already causing deep concern among international students and those hoping to study in the U.S. Roughly 1.1 million international students study at U.S. universities — 6.6% of college students, according to the U.S. Department of Homeland Security's ' Study in the States ' webpage. International enrollment increased by a record 7% last year, according to the Open Doors report cited by the department. International students don't qualify for federal student aid, so the vast majority pay full tuition. That's a lucrative source of revenue for many universities, especially UC campuses, where taxpayers and the university help subsidize the tuition of state residents. Nonresidents pay three times the in-state rate. But the research university system says it also depends upon foreign students for a robust exchange of ideas — academic and cultural. 'The University of California is very concerned about the U.S. State Department's action to pause new interview appointments for applicants for student and exchange visas and the direct impact it will have on our international students, scholars and faculty,' UC officials said through a spokesperson. Sharply reducing the flow of international students is Trump's latest attempt to wrest control of American universities, which he and his allies see as centers of liberal bias. Last year's widespread campus protests against the war in Gaza helped to fuel a claim of systemic antisemitism on campuses. His administration is investigating numerous universities, including UC campuses, seeking evidence to bolster that idea. Trump has also unsuccessfully tried to revoke existing student visas. A Bay Area federal judge blocked that effort last week. Trump has aimed much of his ire at Harvard — including by trying to block new international students from enrolling there — after Harvard's President Alan Garber rebuffed his attempt to take over decision-making powers there last month. Harvard sued twice and won a temporary restraining order. On Thursday, a federal judge extended the order. Now Trump has turned the effort to campuses everywhere. At the White House on Wednesday, he said that American students 'can't get in' to universities 'because we have foreign students there' that take their slots, Bloomberg reported. Trump then suggested that international students should be capped at 15%. 'How did he come up with that number?' asked Shaun Harper, a professor at the University of Southern California's Rossier School of Education. As for international students crowding out U.S. students, 'if that were a problem, I certainly would know,' said Harper, a past president of the Association for the Study of Higher Education. 'It's only suddenly a big problem because Donald Trump has declared it so, as part of his larger war on Harvard University.' Citing college enrollment numbers at the U.S. Department of Education's data site, Harper noted that Harvard's enrollment of foreign students sits at 14% of undergraduates, while schools typically enroll a smaller ratio than that, including UC Berkeley's 12%. At Stanford, 16% of undergraduates are international students. John Aubrey Douglass, senior research fellow at UC Berkeley's Center for Studies in Higher Education, called the halt on international students 'shortsighted and vindictive.' 'We are witnessing an unraveling of a century of a partnership between the federal government and universities and colleges that helped build the world's premier mass higher education system built in part on attracting talent internationally,' he said. In 2017, UC imposed a cap on undergraduate non-state residents, including international students, as it faced a backlash by students and lawmakers who said the university was admitting increasing numbers of nonresidents — who pay full price — at the expense of many Californians. Douglass said this is how the process is supposed to work. 'Let the states decide,' he said. 'And allow independent private schools to make their own enrollment decisions.' On Wednesday, the nonprofit Presidents' Alliance on Higher Education and Immigration said that international students contributed nearly $44 billion to the U.S. economy last year, and supported over 378,000 jobs. The new crackdown on international students is part of a 'growing climate of fear, volatility, and uncertainty' in the country, the group said in a statement, as it urged the Trump administration to reverse its decision.
Yahoo
5 days ago
- Science
- Yahoo
Jupiter designed the solar system. Here's what the planet was like as a child.
Jupiter, the largest planet orbiting the sun, used to be much bigger and stronger when the solar system was just beginning to take shape, a pair of astronomers say. Two scientists at Caltech and the University of Michigan suggest that early Jupiter was at least double its contemporary size. The primitive version of the gas giant could have held some 8,000 Earths within it, said Konstantin Batygin, lead author of the new study. What's more, young Jupiter probably had a magnetic field 50 times more powerful. A magnetic field is an invisible force surrounding a planet that interacts with charged particles coming from the sun and cosmic rays. To calculate those measurements, the scientists looked at how Jupiter's moons move through space and how the planet spins. This unconventional approach, which didn't rely on traditional models, may fill gaps in the solar system's history. Many scientists refer to Jupiter as the "architect" of the solar system because its immense gravity influenced the orbits of other planets and carved up the cloud from which they all emerged. "More than any other planet, Jupiter played a key role in shaping our solar system," Batygin said in a post on X. "Yet details of its early physical state are elusive." SEE ALSO: Private spacecraft circling moon snaps photo with strange optical illusion NASA's Juno spacecraft snaps images of Jupiter and catches the tiny moon Amalthea as it orbits the planet. Credit: NASA / JPL-Caltech / SwRI / MSSS / Gerald Eichstädt The paper, published in the journal Nature Astronomy, rewinds the clock to just 3.8 million years after the first solid objects formed in the solar system and the cloud of gas and dust from which everything formed started to evaporate. This period — when the building materials for planets disappeared — is thought to be a pivotal point, when the general design of the solar system was locked in. Jupiter, roughly 562 million miles from Earth today, has nearly 100 moons. But Batygin and his collaborator Fred Adams' research focused on two of the smaller ones, Amalthea and Thebe. Both are inside the orbit of the much larger moon Io, the most volcanically active world in the solar system, according to NASA. These smaller moons have curiously tilted orbits, and their paths around the planet seem to hold clues about how Jupiter and its bevy of moons moved in the past, Batygin told Mashable. As Io migrates away from Jupiter, its gravity causes a kickback — sort of like how a gun recoils when it's fired — that has contributed to the tilts of the smaller moons. "Similar to how our moon gradually moves away from Earth due to tides, Io is slowly drifting outward from Jupiter," Batygin said. By measuring Amalthea and Thebe's tilted orbits, the scientists reconstructed Io's previous position. That location, they said, should help determine the outer edge of the disk of gas and dust that once surrounded the planet. Based on where they believe the disk ended, the researchers extrapolated how fast Jupiter was spinning back then: about once per day, comparable to its spin now. Knowing Jupiter's early spin also helped them calculate its size. By applying the physics rules of spinning objects, they figured out how big Jupiter had to have been to match that rotation. The size of a young planet sheds light on its heat and interior dynamics as well. The scientists have concluded that early Jupiter must have started out extremely hot — about 2,000 degrees Fahrenheit. That's a far cry from its modern average temperature of about -170 degrees. The heat suggests Jupiter had a much stronger magnetic field. That allowed the team to calculate how fast Jupiter was collecting gas and growing — about the weight of one modern-day Jupiter every million years. "It's astonishing," said Adams in a statement, "that even after 4.5 billion years, enough clues remain to let us reconstruct Jupiter's physical state at the dawn of its existence."
Yahoo
6 days ago
- Science
- Yahoo
Scientists Find Jupiter Used to Be More Than Twice Its Current Size
You don't need us to tell you that Jupiter, which has more than twice the mass of all the other planets in the Solar System combined, is the biggest game in town (other than the Sun, at least.) But believe it or not, it may have once been even bigger. Try more than double its current size, according to new research from Caltech and the University of Michigan — boasting enough volume to fit 2,000 Earths inside it with room to spare. Over time, the bloated world cooled off, contracting to the relatively humbler size it is today. The findings, published in a new study in the journal Nature Astronomy, provide a window into the Solar System's early evolution, around 3.8 million years after the first solids formed. Jupiter, with its enormous gravitational pull — and as the first planet to form — would have played an instrumental role in determining how the orbits of the nascent planets eventually settled. "Our ultimate goal is to understand where we come from, and pinning down the early phases of planet formation is essential to solving the puzzle," co-lead author Konstantin Batygin, a professor of planetary science at Caltech, said in a statement about the work. "This brings us closer to understanding how not only Jupiter but the entire Solar System took shape." The clues to uncovering this early episode of Jupiter's past lie in two of its small moons, Amalthea and Thebe, which exhibit unusual orbits that aren't fully explained by their host's current size. To examine this discrepancy, the researchers bypassed existing planetary formation models and focused on aspects of the Jovian system that could be directly measured, including the orbital dynamics of the tiny moons and the planet's angular momentum. Their calculations revealed that, around 4.5 billion years ago, Jupiter must have had a radius up to 2.5 times greater than it is today. Likewise, its magnetic field — terrifyingly, as it's already 20,000 stronger than the Earth's — would have been a staggering 50 times more powerful. This dramatically shapes our idea of Jupiter in a critical moment in the Solar System's evolution, when the great disk of matter surrounding the Sun called the protoplanetary disk, which gave birth to the planets, evaporated. Mind-boggling as they are, these findings, the researchers say, are consistent with the prevailing core-accretion theory describing how giant planets formed. According to this theory, the giant planets began as heavy, solid cores floating on the farther and colder side of the protoplanetary disk, pulling in the lighter gas molecules surrounding them — first gradually, and then after passing a threshold of mass, much more rapidly. The exact details surrounding the planets' origins are still hotly contested. But the researchers say they've made the most precise measurements to date of primordial Jupiter's size, spin rate, and magnetic conditions, which will be indispensable to furthering our understanding of the Solar System's architecture. "What we've established here is a valuable benchmark," Batygin said. "A point from which we can more confidently reconstruct the evolution of our Solar System." More on astronomy: Astronomers Baffled by a Suspicious, Perfectly Round Sphere in Our Galaxy
