Researchers at the University of Warsaw have achieved a significant milestone in the study of quantum mechanics by creating anti-clockwise twists in light through the superposition of two clockwise-twisted light beams. This breakthrough has opened up new possibilities for observing two-dimensional quantum backflow and holds great promise for applications in optical microscopy and precision timekeeping.
In a recent publication in the prestigious journal Optica, scientists from the University of Warsaw’s Faculty of Physics detailed their groundbreaking experiment. By superposing two light beams twisted in a clockwise direction, they managed to generate anti-clockwise twists in the dark regions of the resulting superposition. This achievement represents a crucial step towards understanding the intricate world of quantum mechanics and harnessing it for practical applications.
The concept of quantum backflow may seem counterintuitive when compared to the behavior of classical objects like a tennis ball. In classical mechanics, objects have well-defined positions, while in quantum mechanics and optics, particles can exist in superposition, occupying multiple positions simultaneously. Quantum particles can exhibit the phenomenon of backflow, where they have a probability of moving backward or spinning in the opposite direction during certain time intervals.
Backflow in quantum systems had not been observed experimentally until this breakthrough. However, it had been successfully demonstrated in classical optics using light beams. The research builds on theoretical work by scientists like Yakir Aharonov, Michael V. Berry, and Sandu Popescu, who explored the relationship between backflow in quantum mechanics and the peculiar behavior of optical waves at local scales.
The researchers employed a Shack-Hartman wavefront sensor to observe the phenomenon, providing high sensitivity for two-dimensional spatial measurements. By superposing two beams of light with negative orbital angular momentum, they observed positive local orbital angular momentum in the dark regions of the interference pattern, a phenomenon they termed ‘azimuthal backflow.’
Historically, light beams with azimuthal phase dependence, carrying orbital angular momentum, were first generated in 1993 by Marco Beijersbergen and have since found applications in various fields, including optical microscopy and optical tweezers, which enable the manipulation of micro- and nanoscale objects.
The study also touches on the concept of superoscillation, where the local oscillation of a superposition is faster than its fastest Fourier component. This phenomenon has potential applications in light-matter interactions, optical trapping, and the design of ultra-precise atomic clocks.
In summary, the University of Warsaw’s groundbreaking research has not only advanced our understanding of quantum mechanics but also opened doors to practical applications in precision technologies. This achievement in observing quantum backflow in two dimensions is a remarkable step forward in the world of quantum physics.
Reference:
“Azimuthal backflow in light carrying orbital angular momentum” by Bohnishikha Ghosh, Anat Daniel, Radek Lapkiewicz, and Bernard Gorzkowski, published in Optica on September 19, 2023.
DOI: doi:10.1364/OPTICA.495710
This research was supported by the Foundation for Polish Science under the FIRST TEAM project ‘Spatiotemporal photon correlation measurements for quantum metrology and super-resolution microscopy,’ co-financed by the European Union under the European Regional Development Fund (POIR.04.04.00-00-3004/17-00).
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Frequently Asked Questions (FAQs) about Quantum Backflow
What is the key achievement of the University of Warsaw’s research?
The University of Warsaw’s research achieved the creation of anti-clockwise twists in light, demonstrating the potential for observing two-dimensional quantum backflow.
What is quantum backflow, and why is it significant?
Quantum backflow is a phenomenon in which quantum particles can exhibit the probability of moving backward or spinning in the opposite direction during certain time intervals. It is significant because it offers insights into the complex world of quantum mechanics and has practical applications in precision technologies.
How did the researchers create anti-clockwise twists in light?
The researchers at the University of Warsaw achieved this by superposing two clockwise-twisted light beams, which resulted in anti-clockwise twists in the dark regions of the superposition.
What are the potential applications of this breakthrough?
This research has applications in optical microscopy and precision timekeeping. It may also have implications for light-matter interactions, optical trapping, and the design of ultra-precise atomic clocks.
Has quantum backflow been observed before this research?
No, quantum backflow had not been observed experimentally before this research. It had been successfully demonstrated in classical optics using light beams, but this breakthrough represents its first experimental observation in quantum systems.
Are there historical references related to the concept of azimuthal phase dependence in light beams?
Yes, light beams with azimuthal phase dependence were first generated by Marco Beijersbergen in 1993. These beams have found applications in various fields, including optical microscopy and optical tweezers.
What is the significance of superoscillation mentioned in the text?
Superoscillation refers to situations where the local oscillation of a superposition is faster than its fastest Fourier component. It has potential applications in light-matter interactions, optical trapping, and ultra-precise atomic clock design.
How was the phenomenon observed in the research?
The researchers used a Shack-Hartman wavefront sensor to observe the phenomenon, providing high sensitivity for two-dimensional spatial measurements.
What publication details should I reference for more information?
You can refer to the publication titled “Azimuthal backflow in light carrying orbital angular momentum” by Bohnishikha Ghosh, Anat Daniel, Radek Lapkiewicz, and Bernard Gorzkowski, published in Optica on September 19, 2023, with the DOI: doi:10.1364/OPTICA.495710.
Was this research financially supported?
Yes, this research was supported by the Foundation for Polish Science under the FIRST TEAM project ‘Spatiotemporal photon correlation measurements for quantum metrology and super-resolution microscopy,’ co-financed by the European Union under the European Regional Development Fund (POIR.04.04.00-00-3004/17-00).
More about Quantum Backflow
- University of Warsaw Faculty of Physics
- Optica Journal
- Shack-Hartman Wavefront Sensor
- Marco Beijersbergen’s Research
- Optical Tweezers
- 2018 Nobel Prize in Physics (Arthur Ashkin)
- Superoscillation
- Professor Michael Berry
- Yakir Aharonov
- Sandu Popescu
- University of Bristol
- Foundation for Polish Science
- European Regional Development Fund
