Scientists have controlled hybrid quantum states in helium using intense ultraviolet lasers, opening new paths in quantum research.
An international team of scientists, led by Dr. Lukas Bruder, a junior research group leader at the University of Freiburg’s Institute of Physics, has successfully created and controlled hybrid electron-photon quantum states in helium atoms.
The team accomplished this by generating specially designed, highly intense extreme ultraviolet light pulses using the FERMI free electron laser in Trieste, Italy. By employing an innovative laser pulse-shaping technique, they were able to precisely control these hybrid quantum states. The groundbreaking findings have been published in 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 centimeter. 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 nanometers, 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 color 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.”
Reference: “Strong-field quantum control in the extreme ultraviolet domain using pulse shaping” by Fabian Richter, Ulf Saalmann, Enrico Allaria, Matthias Wollenhaupt, Benedetto Ardini, Alexander Brynes, Carlo Callegari, Giulio Cerullo, Miltcho Danailov, Alexander Demidovich, Katrin Dulitz, Raimund Feifel, Michele Di Fraia, Sarang Dev Ganeshamandiram, Luca Giannessi, Nicolai Gölz, Sebastian Hartweg, Bernd von Issendorff, Tim Laarmann, Friedemann Landmesser, Yilin Li, Michele Manfredda, Cristian Manzoni, Moritz Michelbach, Arne Morlok, Marcel Mudrich, Aaron Ngai, Ivaylo Nikolov, Nitish Pal, Fabian Pannek, Giuseppe Penco, Oksana Plekan, Kevin C. Prince, Giuseppe Sansone, Alberto Simoncig, Frank Stienkemeier, Richard James Squibb, Peter Susnjar, Mauro Trovo, Daniel Uhl, Brendan Wouterlood, Marco Zangrando and Lukas Bruder, 11 December 2024, Nature.
DOI: 10.1038/s41586-024-08209-y
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.
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3 Comments
Will it bring ze German economy back?
Scientists have controlled hybrid quantum states in helium using intense ultraviolet lasers, opening new paths in quantum research.
Do scientists not need to understand the spacetime background of quantum research?
You guys got too much money. When a constant flow of “dah” flies from every report, there’s a bunch of people with nothing to do.
Let’s see, there’s a ‘shift’ when the natural order of energy states is trapped in 10 to 100 Trillion volt/centimeter laboratory environment – hmm, very surprising.