Scientists first achieved a quantum entanglement of 3,000 atoms using 1 photon
Scientists managed to confuse at a quantum level about 3 thousand atoms with a single photon:
Physicists from the Massachusetts Institute of Technology and the University of Belgrade developed a new technology with which they managed to confuse 2920 atoms at a quantum level simultaneously using one single photon of light. And this number is a kind of record, the largest number of atoms that anyone managed to confuse during research and experiments. Scientists believe that the technology they developed with some adaptation can become a practical way to obtain groups of entangled atoms, which, in turn, can become key components of new high-precision atomic clocks, quantum communication systems and quantum computers.
“It’s almost impossible to achieve the quantum entanglement of 3,000 atoms using one photon by any conventional means,” says Vladan Vuletic, professor at the Faculty of Physics at the Massachusetts Institute of Technology, “But we were able to discover a completely new class of entangled state of quantum objects, which we managed to get by exposure to a single photon. And now we have found and are exploring several more new classes of quantum entanglement, with the help of which it will be possible to create absolutely amazing things. ”
Until recently, many scientists conducted experiments, trying to confuse at the quantum level simultaneously many atoms. This is not to say that these attempts were completely unsuccessful, the previous record was to obtain the quantum entanglement of a group of 100 atoms.
And Professor Vuletik and his colleagues managed to immediately confuse 2910 atoms from the group in which there were 3100 atoms. In doing so, they used a very weak pulse of laser light, a pulse containing one single photon. “The weaker the light we use, the better,” Professor Vuletik says. “A stronger light will most likely destroy the fragile quantum structure of a cloud of atoms, and the whole system remains in a relatively pure quantum state.”
Scientists began entangling atoms by cooling a cloud of atoms and trapping them with a laser trap. Then, a laser pulse consisting of one photon was sent into the bowels of this cloud. This photon, passing through a cloud and interacting along the path with atoms, was captured at the output by a highly sensitive sensor capable of accurately measuring all its characteristics.
If a photon passing through a cloud of atoms does not interact with any of the atoms, its polarization remains unchanged. Otherwise, its polarization is shifted by a certain angle during each interaction with the atom. Naturally, its polarization is also affected by quantum noise created by atoms rotating clockwise and counterclockwise.
“From time to time we observed a photon whose polarization was strictly perpendicular to the angle of its initial polarization,” says Professor Vuletik, “Our calculations showed that such a polarization angle a photon could acquire only under the influence of a group of many entangled atoms, which he himself and confused. "
Now, the Vuletik group is working on overcoming the limitations imposed by the so-called “standard quantum limit”, which determines the accuracy limit of any measurements made within quantum systems, using the method of detecting single photons and the special state of quantum entanglement discovered by them . “This special state of quantum entanglement will increase the accuracy of atomic clocks at least twice,” says Professor Vuletik, “and the other special quantum states that we are currently studying will allow us to increase the accuracy even more times.”
Physicists from the Massachusetts Institute of Technology and the University of Belgrade developed a new technology with which they managed to confuse 2920 atoms at a quantum level simultaneously using one single photon of light. And this number is a kind of record, the largest number of atoms that anyone managed to confuse during research and experiments. Scientists believe that the technology they developed with some adaptation can become a practical way to obtain groups of entangled atoms, which, in turn, can become key components of new high-precision atomic clocks, quantum communication systems and quantum computers.
“It’s almost impossible to achieve the quantum entanglement of 3,000 atoms using one photon by any conventional means,” says Vladan Vuletic, professor at the Faculty of Physics at the Massachusetts Institute of Technology, “But we were able to discover a completely new class of entangled state of quantum objects, which we managed to get by exposure to a single photon. And now we have found and are exploring several more new classes of quantum entanglement, with the help of which it will be possible to create absolutely amazing things. ”
Until recently, many scientists conducted experiments, trying to confuse at the quantum level simultaneously many atoms. This is not to say that these attempts were completely unsuccessful, the previous record was to obtain the quantum entanglement of a group of 100 atoms.
And Professor Vuletik and his colleagues managed to immediately confuse 2910 atoms from the group in which there were 3100 atoms. In doing so, they used a very weak pulse of laser light, a pulse containing one single photon. “The weaker the light we use, the better,” Professor Vuletik says. “A stronger light will most likely destroy the fragile quantum structure of a cloud of atoms, and the whole system remains in a relatively pure quantum state.”
Scientists began entangling atoms by cooling a cloud of atoms and trapping them with a laser trap. Then, a laser pulse consisting of one photon was sent into the bowels of this cloud. This photon, passing through a cloud and interacting along the path with atoms, was captured at the output by a highly sensitive sensor capable of accurately measuring all its characteristics.
If a photon passing through a cloud of atoms does not interact with any of the atoms, its polarization remains unchanged. Otherwise, its polarization is shifted by a certain angle during each interaction with the atom. Naturally, its polarization is also affected by quantum noise created by atoms rotating clockwise and counterclockwise.
“From time to time we observed a photon whose polarization was strictly perpendicular to the angle of its initial polarization,” says Professor Vuletik, “Our calculations showed that such a polarization angle a photon could acquire only under the influence of a group of many entangled atoms, which he himself and confused. "
Now, the Vuletik group is working on overcoming the limitations imposed by the so-called “standard quantum limit”, which determines the accuracy limit of any measurements made within quantum systems, using the method of detecting single photons and the special state of quantum entanglement discovered by them . “This special state of quantum entanglement will increase the accuracy of atomic clocks at least twice,” says Professor Vuletik, “and the other special quantum states that we are currently studying will allow us to increase the accuracy even more times.”