A research team has created a quantum antenna capable of precisely measuring terahertz frequency combs for the first time.
A research team from the Faculty of Physics and the Centre for Quantum Optical Technologies at the Centre of New Technologies, University of Warsaw has introduced a new approach for detecting extremely weak terahertz signals by using a “quantum antenna.” Their method relies on a specialized system that employs Rydberg atoms for radio wave detection, allowing them not only to capture these signals but also to accurately calibrate a frequency comb in the terahertz range.
This part of the electromagnetic spectrum was considered largely unexplored until recently, and the breakthrough, reported in Optica, offers a pathway toward highly sensitive spectroscopy and a new class of quantum sensors that can function at room temperature.
Terahertz (THz) radiation occupies a unique position within the electromagnetic spectrum, sitting between microwaves (such as those used in Wi-Fi) and infrared light at the intersection of electronics and optics. It promises a wide range of applications, including scanning packages without harmful X-rays, enabling ultra-fast 6G communication, and advancing spectroscopy and organic compound imaging.
Despite this potential, using THz radiation for precise and sensitive measurements has remained difficult. Significant advancements in generating and detecting THz waves have been made in recent years, yet achieving an accurate measurement of a frequency comb had remained out of reach until this work.
The Role of Frequency Combs
Why is this so important? Frequency combs, which earned a Nobel Prize in 2005, are most easily visualized as an extremely precise ruler, but one created from light or radio waves. Instead of millimeter markings, one has a series of uniformly spaced lines (“teeth”) at strictly defined frequencies. This “electromagnetic ruler” allows physicists to measure the frequency of an unknown signal with extreme accuracy—simply by checking which “tooth” on the ruler the signal aligns with. As a result, combs serve as a reference standard for calibrating and tuning other devices across a very wide range. Depending on where in the electromagnetic spectrum this ruler is located, we refer to optical, radio, or terahertz frequency combs.
Terahertz frequency combs are particularly interesting because they would enable calibration and, consequently, more precise measurements in a frequency range significantly higher (faster oscillating) than radio waves, yet lower than optical waves (light). However, this type of comb is difficult to measure precisely—it is too fast for modern electronics and, at the same time, cannot be recorded with optical methods. Although the spacing between the comb’s teeth can be determined, and the total power emitted across the spectrum can be measured, it has been challenging to determine the power contribution of a single tooth.
The scientists from the Faculty of Physics and the Centre for Quantum Optical Technologies at the Centre of New Technologies, University of Warsaw successfully overcame this limitation and measured the signal emitted by a single terahertz comb tooth for the first time. To do this, they used a gas of rubidium atoms in a Rydberg state. A Rydberg atom is defined as having a single electron excited to a very high orbit by being illuminated with precisely tuned lasers. This “swollen” atom becomes a quantum antenna, extremely sensitive to external electric fields. Furthermore, using tunable lasers, it can then be tuned to one specific frequency of such a field, in a range extending up to terahertz waves.
Traditionally, in Rydberg electrometry, the phenomenon of Autler-Townes splitting is used to measure the electric field. Its huge advantage is that the measurement result depends only on fundamental atomic constants, providing an absolutely calibrated readout. Unlike classical antennas, which require laborious calibration in specialized radio laboratories, the atomic-based system is, in a sense, a standard unto itself. Moreover, thanks to the richness of energy states in the atom, such a sensor can be tuned almost continuously over an enormous range—from a direct current (DC) signal up to the aforementioned terahertz.
Enhancing Sensitivity Through Light Conversion
However, this method has a limitation: on its own, it is not sensitive enough to record very weak terahertz signals. To remedy this, the research team additionally applied a radio wave-to-light conversion technique invented at the University of Warsaw and adapted it to the needs of terahertz radiation. In this process, the weak terahertz signal is converted into optical photons, which can then be detected with immense sensitivity using single-photon counters.
This hybrid approach is the key to success: it combines the extreme sensitivity of photon detection with the ability to “recover” the calibration capabilities of the Autler-Townes method even for the weakest signals.
Mapping and Calibrating the Terahertz Comb
The sensor based on Rydberg atoms possesses all the features needed to perform precise frequency comb calibration: it can be tuned to a single tooth of the comb, and then retuned to the next, and the next. The scientists managed to observe several dozen teeth in a very wide frequency range this way. Additionally, thanks to the knowledge of the fundamental properties of atoms, the comb was directly calibrated, precisely determining its intensity.
The results obtained by the physicists from the University of Warsaw Wiktor Krokosz, Jan Nowosielski, Bartosz Kasza, Sebastian Borówka, Mateusz Mazelanik, Wojciech Wasilewski, and Michał Parniak are more than just another sensitive detector.
They are the foundation for a new branch of metrology. Thanks to the advantages of Rydberg atoms, the revolutionary applications of optical frequency combs can now be transferred to the hitherto difficult terahertz domain. Crucially, unlike many quantum technologies requiring extremely low temperatures, the developed system operates at room temperature, which drastically reduces costs and facilitates future commercialization. This opens the door to creating reference measurement standards for the upcoming era of terahertz technologies.
Reference: “Electric-field metrology of a terahertz frequency comb using Rydberg atoms” by Bartosz Kasza, Michał Parniak, Wojciech Wasilewski, Mateusz Mazelanik, Jan Nowosielski, Wiktor Krokosz and Sebastian Borówka, 19 November 2025, Optica.
DOI: doi:10.1364/OPTICA.578051
The project “Quantum Optical Technologies” (FENG.02.01-IP.05-0017/23) is implemented as part of Measure 2.1 International Research Agendas of the Foundation for Polish Science, co-financed by the European Union from Priority 2 of the European Funds for Modern Economy Program 2021–2027 (FENG). The research is also one of the results of the SONATA17 and PRELUDIUM23 projects funded by the National Science Centre.)
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3 Comments
The sensor based on Rydberg atoms possesses all the features needed to perform precise frequency comb calibration: it can be tuned to a single tooth of the comb, and then retuned to the next, and the next.
VERY GOOD!
Please ask researchers to think deeply:
1. Why do radio waves have frequencies and periods?
2. Are they related to the spin of atoms?
3. Why do atoms spin?
4. Why do topological vortices spin?
5. Is atomic spin related to topological spin?
6. What is the spacetime background of topological spin in the universe?
7. Are atoms high-dimensional spacetime matter or low dimensional spacetime matter?
8. Is topological vortex high-dimensional spacetime matter or low dimensional spacetime matter?
9. Can low dimensional spacetime matter be the basis of high-dimensional spacetime matter?
10. What is the spacetime background of radio wave propagation?
and so on.
When we pursue the ultimate truth of all things, the space in which our bodies and all things exist may itself be the final and deepest puzzle we need to explore. This is not only the pursuit of physics, but also the most magnificent exploration of the origin of the universe by human reason.
Based on the Topological Vortex Theory (TVT), space is an uniformly incompressible physical entity. Space-time vortices are the products of topological phase transitions of the tipping points in space, are the point defects in spacetime. Point defects do not only impact the thermodynamic properties, but are also central to kinetic processes. They create all things and shape the world through spin and self-organization.
In today’s physics, some so-called peer-reviewed journals—including Physical Review Letters, Nature, Science, and others—stubbornly insist on and promote the following:
1. Even though θ and τ particles exhibit differences in experiments, physics can claim they are the same particle. This is science.
2. Even though topological vortices and antivortices have identical structures and opposite rotational directions, physics can define their structures and directions as entirely different. This is science.
3. Even though two sets of cobalt-60 rotate in opposite directions and experiments reveal asymmetry, physics can still define them as mirror images of each other. This is science.
4. Even though vortex structures are ubiquitous—from cosmic accretion disks to particle spins—physics must insist that vortex structures do not exist and require verification. Only the particles that like God, Demonic, or Angelic are the most fundamental structures of the universe. This is science.
5. Even though everything occupies space and maintains its existence in time, physics must still debate and insist on whether space exists and whether time is a figment of the human mind. This is science.
6. Even though space, with its non-stick, incompressible, and isotropic characteristics, provides a solid foundation for the development of physics, physics must still insist that the ideal fluid properties of space do not exist. This is science.
and go on.
Is this the counterintuitive science they widely promote? Compromising with pseudo academic publications and peer review by pseudo scholars is an insult to science and public intelligence. Some so-called scholars no longer understand what shame is. The study of Topological Vortex Theory (TVT) reminds us that the most profound problems in physics often lie at the intersection of different theories. By exploring these border regions, we can not only resolve contradictions in existing theories but also discover new physical phenomena and application possibilities.
Under the topological vortex architecture, it is highly challenging for even two hydrogen atoms or two quarks to be perfectly symmetrical, let alone counter-rotating two sets of cobalt-60. Contemporary physics and so-called peer-reviewed publications (including Physical Review Letters, Science, Nature, etc.) stubbornly believe that two sets of counter rotating cobalt-60 are two mirror images of each other, constructing a more shocking pseudoscientific theoretical framework in the history of science than the “geocentric model”. This pseudo scientific framework and system have seriously hindered scientific progress and social development.
For nearly a century, physics has been manipulated by this pseudo scientific theoretical system and the interest groups behind it, wasting a lot of manpower, funds, and time. A large amount of pseudo scientific research has been conducted, and countless pseudo scientific papers have been published, causing serious negative impacts on scientific and social progress, as well as humanistic development.
Complexity does not necessarily mean that there is no logical and architectural framework to follow. Mathematics is the language and tool that reveals the motion of spacetime, rather than the motion itself. Although the physical form of spacetime vortices is extremely simple, their interaction patterns are highly complex, and we must develop more and richer mathematical languages to describe and understand them.
The development of the Topological Vortex Theory (TVT) reflects a progression from concrete physical phenomena to abstract mathematical modeling and, ultimately, to interdisciplinary unification. Its core innovation lies in forging the continuous spacetime geometry of general relativity with the discrete interactions of quantum field theory within the same topological dynamical system.
——Excerpted from https://scitechdaily.com/microscope-spacecrafts-most-precise-test-of-key-component-of-the-theory-of-general-relativity/#comment-909171.
B Memo 2512111204_Source 1. Reinterpretation []
Source 1.
https://scitechdaily.com/quantum-antenna-breaks-barrier-in-measuring-elusive-terahertz-signals/
1.
“Quantum Antenna” Breaks Barriers to Measuring Elusive Terahertz Signals
_A frequency comb converted into light by a cell containing rubidium atoms.
_A research team has developed the first quantum antenna capable of accurately measuring terahertz frequency comb teeth.
_A research team from the Department of Physics and the Center for Quantum Optics at the University of Warsaw’s Center for New Technologies has developed a new approach to detecting extremely weak terahertz signals using a “quantum antenna.”
_The method is based on a specialized system that uses Rydberg atoms for radio wave detection, enabling not only signal capture but also the precise calibration of frequency combs in the terahertz band.
[The Rydberg atom is msbase.mode. A Rydberg atom is an excited atom with one or more electrons, each with a very high principal quantum number, n. The higher the value of n, the farther the electron is from the nucleus, on average.]
The relationship between these two is formalized by measuring the wavelength emitted by the atom and expressing it in a formula. Using hydrogen atoms, it describes the wavelength emitted when a hydrogen atom transitions from one energy level to another.
>>msbase has a wavelength, but it doesn’t originate from a single atom. The mbshell, which corresponds to a quantum level, has a wavelength range and a long frequency range, similar to qpeoms.1.
>>>Frequency is determined by magicsum.1. The frequencies that produce fluctuations have the same starting point, like the base of an equilateral triangle.
And the finish line is the same. It’s like a marathon race, where countless feet step in and out of the circle, gradually reducing the number of runners at the base. Oh, my.
, the metaphor seems to have shifted, but the implication is that many variables are not just arrays of msbases, since frequency is not a single wavelength.
1244,50]
This part of the electromagnetic spectrum was considered largely unexplored until recently, and this groundbreaking discovery, reported in Optica, points the way toward high-sensitivity spectroscopy and a new class of quantum sensors capable of operating at room temperature.
1-1.
Terahertz (THz) radiation occupies a unique position within the electromagnetic spectrum, at the intersection of electronics and optics, between microwaves (e.g., Wi-Fi) and infrared.
It promises a wide range of applications, including scanning packages without harmful X-rays, enabling ultra-high-speed 6G communications, and advancing spectroscopy and organic compound imaging.
Despite this potential, making precise and sensitive measurements using terahertz radiation remains a challenging task.
Although terahertz wave generation and detection technology has advanced significantly in recent years, accurate measurement of frequency combs remained a challenging task until this research.
1-2. The Role of Frequency Combs
Why is this so important? Frequency combs, for which the 2005 Nobel Prize was awarded, are most easily visualized by a very precise ruler, but they are actually made of light or radio waves.
Instead of markings in millimeters, they feature a series of evenly spaced lines (“teeth”) at strictly defined frequencies. This “electromagnetic comb” allows physicists to measure the frequency of an unknown signal with great precision.
This is possible simply by determining which “teeth” on the ruler the signal matches. Consequently, the comb serves as a reference standard for calibrating and adjusting other devices over a very wide range. Depending on where this ruler is located in the electromagnetic spectrum, it is called an optical comb, a radio comb, or a terahertz frequency comb.
[ magicsum.value.n_interval in msbase
A matrix is like a ruler.
I didn’t know the frequency comb spacing was in msbase.msoss.qpeoms.side. How fun!!
The magicsum comb spacing is so wide that it provides a standard for the comb spacing of the timespace we want to measure. Even the smallest timescale can provide coordinates in the pan-dimensional pms.instanton.newton’s_crandle.levels, just like instantans. Ugh.
1311,1337,40, 1423,26]
1-3.
_Terahertz frequency combs are particularly interesting because they enable calibration and more precise measurements in a frequency range much higher (faster oscillation) than radio waves and lower than optical waves (light).
_However, precise measurements with this type of comb are difficult. They are too fast for modern electronic equipment, and at the same time, they cannot be measured using optical methods.
While measuring the comb spacing and the total power emitted across the spectrum is possible, measuring the power contribution of a single comb has been challenging.
2.
Scientists from the Department of Physics and the Center for Quantum Optics at the University of Warsaw’s Center for New Technologies have overcome these limitations and achieved the first measurement of a signal emitted from a single terahertz comb. They used a gas of rubidium atoms in the Rydberg state.
2-1.
A Rydberg atom is defined as one with a single electron excited to a very high orbital by a precisely tuned laser.
This “inflated” atom becomes a quantum antenna that is highly sensitive to external electric fields. Furthermore, using a tunable laser, it can be tuned to electric fields of specific frequencies extending into the terahertz range.
3. Terahertz Comb Mapping and Calibration
Rydberg atom-based sensors possess all the capabilities necessary for precise frequency comb calibration. After adjusting to one tooth of the comb, it can be adjusted to the next tooth, and then the next. This approach allowed scientists to observe dozens of teeth across a very wide frequency range.
Furthermore, thanks to their knowledge of the fundamental properties of atoms, they were able to directly calibrate the comb teeth and precisely measure their intensity.
Importantly, unlike many quantum technologies that require cryogenic temperatures, the developed system operates at room temperature, significantly reducing costs and facilitating future commercialization. This opens the door to developing a reference measurement standard for the coming era of terahertz technology.