Since Erwin Schroedinger's famous 1935 cat thought experiment, physicists around the globe have tried to create large scale systems to test how the rules of quantum mechanics apply to everyday objects.
Researchers at the University of Calgary recently made a significant step forward in this direction by creating a large system that is in two substantially different states at the same time. Until this point, scientists had only managed to recreate quantum effects on much smaller scales.
Professor Alex Lvovsky and associate professor Christoph Simon from the Physics and Astronomy department together with their graduate students revealed their findings in a world leading physics research journal, Nature Physics.
Understanding Schroedinger's cat
In contrast to our everyday experience, quantum physics allows for particles to be in two states at the same time – so-called quantum superpositions. A radioactive nucleus, for example, can simultaneously be in a decayed and non-decayed state.
Applying these quantum rules to large objects leads to paradoxical and even bizarre consequences. To emphasize this, Erwin Schroedinger, one of the founding fathers of quantum physics, proposed in 1935 a thought experiment involving a cat that could be killed by a mechanism triggered by the decay of a single atomic nucleus. If the nucleus is in a superposition of decayed and non-decayed states, and if quantum physics applies to large objects, the belief is that the cat will be simultaneously dead and alive.
While quantum systems with properties akin to 'Schroedinger's cat' have been achieved at a micro level, the application of this principle to everyday macro objects has proved to be difficult to demonstrate.
"This is because large quantum objects are extremely fragile and tend to disintegrate when subjected to any interaction with the environment," explains Lvovsky.
Photons help to illuminate the paradox
The breakthrough achieved by Calgary quantum physicists is that they were able to contrive a quantum state of light that consists of a hundred million light quanta (photons) and can even be seen by the naked eye. In their state, the "dead" and "alive" components of the "cat" correspond to quantum states that differ by tens of thousands of photons.
"The laws of quantum mechanics which govern the microscopic world are very different from classical physics that rules over large objects such as live beings," explains lead author Lvovsky. "The challenge is to understand where to draw the line and explore whether such a line exists at all. Those are the questions our experiment sheds light on," he states.
While the findings are promising, study co-author Simon admits that many questions remain unanswered.
"We are still very far from being able to do this with a real cat," he says. "But this result suggests there is ample opportunity for progress in that direction."
Professor Alex Lvovsky is out of the country and best reached on demand by phone, skype and email on Thursday and Friday between 7 a.m and 4 p.m. EST.
Associate professor Christoph Simon is in Calgary and available on demand in person, by phone, skype and email.
Media ContactMarie-Helene Thibeault
For more information, visit ucalgary.ca. Stay up to date with University of Calgary news headlines on Twitter @UCalgary and in our media centre at ucalgary.ca/news/media.
Marie-Helene Thibeault | EurekAlert!
Astronomers release most complete ultraviolet-light survey of nearby galaxies
18.05.2018 | NASA/Goddard Space Flight Center
A quantum entanglement between two physically separated ultra-cold atomic clouds
17.05.2018 | University of the Basque Country
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology