Superfluid–to–Mott Insulator Transition
This paper reports a technical and scientific innovation in the use of ultracold atomic gases to investigate important quantum phase transitions, such as the ones that produce superfluidity. The authors demonstrate the ability to monitor atoms trapped in an optical lattice at the single-site level and reveal the emergence of a specific insulating phase. Their approach will have a tremendous impact on the field of quantum gases.
How to win a coin game called atomic clock
If you flip a hundred coins, you are unlikely to get exactly fifty heads and fifty tails; there is a statistical uncertainty in the outcome. Researchers at MIT have reduced the statistical uncertainty in the quantum mechanical equivalent of a coin toss.
A Magnetic Gas
For decades, it has been an open question whether it is possible for a gas to show properties similar to a magnet made of iron or nickel. Iron and nickel are ferromagnetic because they become strongly magnetized below a specific temperature, when unpaired electrons within the material spontaneously align in the same direction.
Buffer-gas Cooled Bose-Einstein Condensate
Now well into its second decade, the experimental realization of Bose-Einstein condensation (BEC) in dilute gases has led to revolutionary advances in physics. Since this achievement the field has moved quickly, with innumerable new developments in coherent atom and molecular optics and nonlinear atom optics, the observation of superfluidity in atomic gases, the study of novel quantum systems, and most recently the study of the BEC-BCS crossover.
Despite the breadth of new research, however, the basic recipe for BEC is unchanged from its first realization in alkali atoms: pre-cool a hot sample utilizing laser cooling to permit trapping and provide high densities, followed by evaporative cooling to reach quantum degeneracy.
Viewpoint: Heralding the storage of light
This design of atomic quantum memory tells us when a pulse of light has been successfully stored and then proceeds to retrieve it without significantly affecting its polarization. The exquisite operation provides a new capability for quantum information networks.
A quantum network, a possible precursor of a “quantum internet” , relies on mapping the quantum state of a light pulse onto nodes in material systems. In recent years scientists have studied different materials and architectures with the aim of addressing this goal. Catching a beam of light is a central piece of this puzzle; “heralding” it, i.e., finding a signal to know that it has been caught, is more difficult. In a paper published in Physical Review Letters, Haruka Tanji, Saikat Ghosh, Jonathan Simon, Benjamin Bloom, and Vladan Vuletić at MIT, in the US, demonstrate an atomic quantum memory where the successful storage of a light beam is heralded . This capability will likely benefit scalable quantum networking, where it is crucial to know if operations have succeeded.
Swimming in the Fermi sea
Our world is run by electrons. Whether we switch on a light, browse the internet or play music on the iPod, it is electrons moving through the wires, chips and headphones. But how do electrons actually get from A to B?
Viewpoint: Optical switching with cold atoms
At room temperature and atmospheric pressure, atoms travel hundreds of meters per second and collide frequently with one another and their surroundings. Although this unceasing thermal motion keeps us warm, it causes serious problems for anyone trying to probe the internal state of an atom.
When one electron is not enough ….
Most research involving ultra-cold matter has been done with atoms with one active electron (i.e. an electron outside a closed shell of electrons). New theoretical work by CUA researchers has demonstrated that atoms with two active electrons (the so called alkaline-earth atoms) have unique properties that enable the realization of novel quantum processors and for the simulation of new materials.
MIT physicists create new form of matter
MIT scientists have brought a supercool end to a heated race among physicists: They have become the first to create a new type of matter, a gas of atoms that shows high-temperature superfluidity.