On October 7, the Royal Swedish Academy of Sciences announced the names of the new Nobel Prize winners in physics. Brit John Clarke, Frenchman Michel H. Devoret, and American John M. Martinis received a medal and 11 million Swedish kronor (approximately one million euros) "for the discovery of macroscopic quantum mechanical tunneling and energy quantization in an electrical circuit."
Quantum mechanics is currently one of the most complicated scientific disciplines, if not the most complicated. Unlike the macroscopic level familiar to humans, atoms and subatomic particles behave completely differently, as if they were not subject to Newtonian forces and the laws of "normal" physics.
The kingdom of crooked mirrors
Subatomic particles—especially photons (particles of light), and in some cases even "ordinary" electrons—exhibit what is known as wave-particle duality. A common experiment to describe this paradoxical behavior is the double-slit experiment.
An experiment conducted by physicist Thomas Young in 1803 showed that when light passes through two slits, each slit acts as a quasi-source of light and their wavelengths multiply when they hit the opposite surface – this is called interference.
However, later experiments of this type revealed that electrons behave in a similar way. Although they are commonly perceived as "particles" – which, after detaching from an atom, contribute to effects such as combustion or electricity – in Young's experiment, two electrons "emerged" from one electron, which then overlapped.
Heisenberg's uncertainty principle is another well-known "incomprehensible" phenomenon. In 1927, Nobel Prize winner Werner Karl Heisenberg proved that when measuring the position of a particle in space, it is not possible to simultaneously measure its velocity (momentum) and vice versa.
Equally well known is the Einstein-Podolsky-Rosen paradox: if there are two quantum systems and scientists perform a measurement in one, the resulting state has an immediate effect on the state in the other system. This corresponds to another paradoxical theory known as quantum entanglement. Particles in the system under investigation cannot be described independently, but only as part of that system.
With its bizarre phenomena, quantum mechanics ultimately resembles works such as Alice in Wonderland or The Kingdom of Crooked Mirrors. As Richard Feynman, one of the pioneers of this discipline, is said to have said: "If you think you understand quantum physics, you don't understand it." It is therefore fascinating to observe these paradoxes in a system that is visible to the naked eye.
The chip experiment
According to the Royal Swedish Academy of Sciences, one of the main questions in quantum mechanics today is "the maximum size of a system that can demonstrate quantum mechanical effects." The main representatives of the experimental side of this science are facilities such as CERN in Switzerland, which works with scales corresponding to the size of the "space" of subatomic particles.
In the mid-1980s, however, Clarke, Devoret, and Martinis conducted a series of experiments with an electronic chip circuit on which they observed quantum effects on the largest scale to date.
The circuit used by the three physicists in 1984 and 1985 was constructed from superconductors, i.e., materials that conduct electricity with zero resistance. The individual superconducting components were separated in the chip by a thin layer of non-conductive insulator, "a design known as a Josephson junction," the academy explained.
In Newtonian space, it would not be possible for individual particles to leave their "parent" atom without the addition of a large amount of energy. In quantum space, however, this is possible, and the passage of a particle through a barrier is called tunneling.
Charged particles, in this case electrons, passed through the superconductor as if they were a single particle filling the entire circuit, even though their own circuit particles—the nuclei of atoms—should have been in their way.
Electric current was present in the chip without any voltage, but the moment the electrons crossed the non-conductive barrier, the voltage rose noticeably. In this way, Clarke, Devoret, and Martinis proved that the behavior of electricity in the chip is conditioned by the quantum behavior of electrons. According to the Swedish Academy, this also offers opportunities for further development of quantum technologies.
History of Nobel Prizes in Physics
Swedish chemist and engineer Alfred Bernhard Nobel was a staunch pacifist at the end of his life. When his brother Ludvig died in 1888 (he had a heart attack in Paris), French newspapers reportedly published an obituary with the wrong name—Alfred's.
The newspapers in the erroneous obituary described Alfred Nobel as a "merchant of death" who "got rich by inventing new ways for people to kill each other." It was he who mixed the first dynamite in 1867, and it should be added that it was not the only explosive or military technology he created.
The website of his foundation contains a complete list of patents that prove his focus on weapons – from self-propelled projectiles with their own rotation [ammunition of this type with a spiral cut is now common ammunition, ed. to a prototype cartridge with insulated gunpowder, the first rocket prototypes, and even an iron ore purification system.
So when Alfred Nobel read his obituary, he realized the importance of his inventions and wrote a will stipulating that the proceeds from his estate be awarded annually to scientists who had made the greatest contribution to the welfare of mankind in the previous year. In his last will and testament, he also listed the categories of scientific disciplines in which scientists could earn his award.
The Nobel Prize can be awarded for physics, chemistry, physiology or medicine, literature, and peace. In 1969, the Royal Swedish Bank established a separate Prize in Economic Sciences in memory of Alfred Nobel. It is unofficially called the Nobel Prize in Economics.
The story about the mistaken obituary is just a legend, but Nobel's will is real. At that time, Sweden and Norway were in a personal union, and after lengthy negotiations between political representatives, the following system was established: the Peace Prize is awarded by the Nobel Committee, appointed annually by the Norwegian Parliament, while the other prizes are awarded by the Swedish Academy.
With the exception of economics—which was allegedly created as a substitute for the non-existent prize for mathematics—the list of prizes awarded dates back to 1901. That year, the prize for physics was awarded to German experimental physicist Wilhelm Röntgen for his discovery of high-frequency radiation, which he called "X-rays" and which are now named after him.
Other world-renowned physicists undoubtedly include Frenchman Henri Becquerel "for the discovery of spontaneous radioactivity" and the Curies, who worked with his discovery. All three won the prize in 1903.
We should also mention Guglielmo Marconi and Karl Ferdinand Braun, who were awarded the prize in 1909 for "wireless telegraphy," Max Planck, the discoverer of "quanta" (subatomic particles), Albert Einstein for his discovery of the photoelectric effect (1921), Niels Bohr for revealing the structure of the atom (1922), Heisenberg for discovering hydrogen isotopes (1932), Erwin Schrödinger and Paul Dirac for developing atomic theory (1933), Enrico Fermi for his discovery that neutrons can cause radioactive decay (1938), Pavel Cherenkov and colleagues for their discovery of the eponymous radiation (1958), Roger Penrose for calculations confirming the connection between the formation of black holes and the general theory of relativity (2020), and many others.
The laureates from the 1920s to the 1940s are also known for their collaboration on the application of quantum physics theories in the development of the first atomic bomb (Manhattan Project).
Several Nobel Prize winners in physics have been featured in the popular series The Big Bang Theory, notably George Smoot (2008) for his discovery of the "black body," Saul Perlmutter (2011) for proving the expansion of the universe, and Kip Thorne (2017) for confirming the existence of gravitational waves. The series also featured Chemistry Prize winner Frances Arnold, who mimicked the effect of "natural selection" in the development of enzymes and won the prize in 2018 for "directed evolution."