(Press-News.org) An international team of scientists headed by Dr. Lukas Bruder, junior research group leader at the Institute of Physics, University of Freiburg, has succeeded in producing and directly controlling hybrid electron-photon quantum states in helium atoms. To this end, they generated specially prepared, highly intense extreme ultraviolet light pulses using the FERMI free electron laser in Trieste, Italy. The researchers achieved control of the hybrid quantum states using a new laser pulse-shaping technique. Their results have been published in the journal Nature.
Strong light fields can create new quantum states
As long as electrons are bound to an atom, their energy can only be of certain values. These energy values depend primarily on the atoms themselves. However, if an atom is in the beam of a very intense laser, the energy levels shift. Hybrid electron-photon states are created, known as ‘dressed states’. These occur at laser intensities in the range of ten to a hundred trillion watts per square centimetre. In order to be able to produce and control these special quantum states, laser pulses are necessary that achieve such intensities within a short time window of only a few trillionths of a second.
Free electron laser for producing laser radiation in the extreme ultraviolet range
For their experiment, the scientists used the FERMI free electron laser which allows generation of laser light in the extreme ultraviolet spectral range at very high intensity. This extreme ultraviolet radiation has a wavelength of less than 100 nanometres, which is necessary to manipulate the electron states in helium atoms.
In order to control the electron-photon states, the researchers used laser pulses that dispersed or contracted depending on the scenario. To this end, they adjusted the time lag of the different colour components of the laser radiation. The properties of the laser pulses were controlled using a ‘seed laser pulse’, which preconditioned the emission of the free electron laser.
“Our research enabled us for the first time to directly control these transient quantum states in a helium atom,” says Bruder. “The technique we’ve developed opens up a new field of research: this includes new opportunities for making experiments with free electron lasers more efficient and selective or for gaining new insights into fundamental quantum systems, which are not accessible with visible light. In particular it may now be possible to develop methods to study or even control chemical reactions with atomic precision.”
Original publication: Richter et al., Strong-field quantum control in the extreme ultraviolet using pulse shaping. Nature, 2024. DOI.org/10.1038/s41586-024-08209-y
The authors Fabian Richter, Sarang Dev Ganeshamandiram, Nicolai Gölz, Dr. Sebastian Hartweg, Prof. Dr. Bernd von Issendorff, Friedemann Landmesser, Yilin Li, Moritz Michelbach, Arne Morlok, Aaron Ngai, Prof. Dr. Giuseppe Sansone, Prof. Dr. Frank Stienkemeier, Daniel Uhl, Brendan Wouterlood and Dr. Lukas Bruder research at the Institute of Physics at the University of Freiburg. Likewise involved in the publication were researchers from the Max Planck Institute for Physics of Complex Systems in Dresden, the University of Oldenburg, the IFN-CNR in Milan, the University of Innsbruck, the University of Gothenburg, the CNR-IOM Trieste, the Istituto Nazionale die Fisica Nucleare in Rome, the Deutsches Elektronen-Synchrotron DESY in Hamburg, the Hamburg Centre für Ultrafast Imaging, the University of Aarhus and the University of Hamburg.
The research was funded by among others the Federal Ministry of Education and Research (BMBF) LoKo-FEL (05K16VFB) and STAR (05K19VF3), the European Research Council (ERC) Starting Grant MULTIPLEX (101078689), the German Research Foundation (DFG) RTG 2717, Grant 429805582 (project SA 3470/4-1) and project STI 125/24-1 and the Baden-Württemberg Foundation’s elite program for postdocs.
Contact
University and Science Communications
University of Freiburg
Tel.: +49 761 203 4302
E-Mail: kommunikation@zv.uni-freiburg.de
END
Researchers succeed in controlling quantum states in a new energy range
2024-12-12
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Do animals get jealous like people? Researchers say it’s complicated.
2024-12-12
It’s a question that has puzzled thinkers for centuries: Are we humans alone in our pursuit of fairness and the frustration we feel when others get what we want?
In recent years, evolutionary psychologists have suggested that we’re not all that special. Animals, from corvids to capuchin monkeys, express what humans might recognize as jealousy when, for example, they are passed over for a sought-after snack. Many argue this is evidence we are not alone in our aversion toward unfairness.
But new research from the University of California, Berkeley, makes the case that humans might be unique after all.
Using data from ...
Social risks impede cancer screening, even with access to care
2024-12-12
Researchers at University of California San Diego and collaborating institutions have shed light on the ways that social risks, such as housing or food insecurity, pose barriers to routine cancer screenings. The study, published in JNCI Cancer Spectrum, found that patients experiencing social risks were less likely to receive orders for cancer screenings and even less likely to complete screenings when ordered. The study also found that patients experiencing social risks had higher rates of primary care ...
Examining gender inequality in academic publishing
2024-12-12
Editors of academic journals hold an influential position in their field. They have decision-making power over which authors and papers get published, set journal policy, and help shape the trajectory of their discipline. It is also a role in which women are frequently underrepresented.
Assistant professor of accounting Sebastian Tideman-Frappart and several colleagues set out to fill a knowledge gap about this issue in the field of management science by tracking gender diversity in world-leading management journals over time. The resulting article – co-authored by Brooke Gazdag, associate professor of management at Kühne Logistics University; Jamie Gloor, assistant professor ...
UH researchers characterize keys to successful pregnancy in humpback whales
2024-12-12
In a breakthrough study published this week in The Journal of Physiology, researchers at the Marine Mammal Research Program (MMRP) at the University of Hawaiʻi at Manoa's Hawaiʻi Institute of Marine Biology (HIMB) demystify the energetic cost of humpback pregnancy and shed light on the unique vulnerabilities of migratory humpback mothers-to-be. With an arsenal of tools that range from cutting-edge technology to historical whaling records, the research was done in close partnership with Alaska ...
Policy Forum: Considering risks of “mirror life” before it is created
2024-12-12
In a Policy Forum, scientists discuss lifeforms composed of mirror-image biological molecules – also known as “mirror life” – and say creation of such lifeforms, which could evade immune mechanisms and predators, warrants careful consideration. The hallmark of mirror organisms is reversed chirality – a feature that would render them resistant to normal forms of biological degradation, making them useful for applications like long-lasting therapies. While these organisms haven’t yet been observed in nature, and the capability to create them is likely at least ...
Breakthrough of the Year: A drug that prevents HIV infection, providing six months of protection per shot
2024-12-12
As its 2024 Breakthrough of The Year, Science has named the development of lenacapavir – a promising new injectable drug that prevents HIV infection. The award also recognizes related work surrounding gaining a new understanding of the structure and function of HIV’s capsid protein. Despite decades of advancements, HIV continues to infect more than a million people annually, with a vaccine remaining elusive. However, a new injectable drug, lenacapavir, offers hope by providing six ...
Heatwave led to catastrophic and persistent loss of Alaska’s dominant seabird
2024-12-12
The 2014-2016 Pacific marine heatwave wiped out more than half – roughly 4 million – of Alaska’s common murre (Uria aalge) seabirds, representing the largest documented vertebrate die-off linked to warming oceans, according to a new study. “Although research on the impacts of global warming on marine birds has clearly suggested major shifts in species’ ranges and abundance, documented changes have been gradual (years to decades),” write the authors. “To our knowledge, this study is the first to show that climate impacts can be swift (1 ...
Genomic analysis refines timing of Neandertal admixture – and its impact on modern humans
2024-12-12
A genomic study encompassing more than 300 genomes spanning the last 50,000 years has revealed how a single wave of Neandertal gene flow into early modern humans left an indelible mark on human evolution. Among other findings, the study reports that modern humans acquired several Neanderthal genes that ended up being advantageous to our lineage, including those involved in skin pigmentation, immune response, and metabolism. To date, sequencing of Neanderthal and Denisovan genomes has revealed substantial gene flow between these archaic hominins ...
Superflares once per century
2024-12-12
There is no question that the Sun is a temperamental star, as alone this year’s unusually strong solar storms prove. Some of them led to remarkable auroras even at low latitudes. But can our star become even more furious? Evidence of the most violent solar “tantrums” can be found in prehistoric tree trunks and in samples of millennia-old glacial ice. However, from these indirect sources, the frequency of superflares cannot be determined. And direct measurements of the amount of radiation reaching the Earth from the Sun have only been available since the ...
A new timeline for Neanderthal interbreeding with modern humans
2024-12-12
A new analysis of DNA from ancient modern humans (Homo sapiens) in Europe and Asia has determined, more precisely than ever, the time period during which Neanderthals interbred with modern humans, starting about 50,500 years ago and lasting about 7,000 years — until Neanderthals began to disappear.
That interbreeding left Eurasians with many genes inherited from our Neanderthal ancestors, which in total make up between 1% and 2% of our genomes today.
The genome-based estimate is consistent with archeological evidence that modern humans and Neanderthals lived side-by-side in Eurasia for between 6,000 and 7,000 years. The analysis, which involved present-day human genomes ...