News & Research Highlights

Research associate Bo Yan and his colleagues recently observed spin exchanges in ultracold potassium-rubidium (KRb) molecules inside an optical lattice (a crystal of light formed by interacting laser beams). In solid materials, such spin exchanges are the building blocks of advanced materials and exotic behavior.

Because quantum mechanics is crucial to understanding the behavior of everything in the Universe, one can understand key elements of the behavior of a neutron star by investigating the behavior of an atomic system in the laboratory. This is the promise of the new quantum simulator in the Ye labs. It is a fully controllable quantum system that is being used as a laboratory to study the behavior of other less controllable and more poorly understood quantum systems.

Theorist Ana Maria Rey has been given the 2013 “Great Minds in STEM” Most Promising Scientist Award. The honor is also known as the HENAAC (Hispanic Engineer National Achievement Awards Conference) Award.

In the future, quantum microwave networks may handle quantum information transfer via optical fibers or microwave cables. The evolution of a quantum microwave network will rely on innovative microwave circuits currently being developed and characterized by the Lehnert group. Applications for this innovative technology could one day include quantum computing, converters that transform microwave signals to optical light while preserving any encoded quantum information, and advanced quantum electronics devices.

Many people are familiar with the beautiful harmonies created when two sound waves interfere with each other, producing a periodic and repeating pattern that is music to our ears. In a similar fashion, two interfering x-ray waves may soon make it possible to create the fastest possible strobe light ever made. This strobe light will blink fast enough to allow researchers to study the nuclei of atoms and other incredibly tiny structures. The new strobe light is actually very fast coherent laser-like radiation created by the interference of high-energy x-ray waves.

The quantum world is not quite as mysterious as we thought it was. It turns out that there are highways into understanding this strange universe. And, graduate students Minghui Xu and David Tieri with Fellow Murray Holland have just discovered one such superhighway that has been around since the 1950s. Traveling along this superhighway has made it possible to understand the quantum behavior of hundreds of atoms inside every laser used in JILA, including the superradiant laser in the Thompson lab that works entirely differently from all the others.

The Ye group has opened a new gateway into the relatively unexplored terrain of ultracold chemistry. Research associate Matt Hummon, graduate students Mark Yeo and Alejandra Collopy, newly minted Ph.D. Ben Stuhl, Fellow Jun Ye, and a visiting colleague Yong Xia (East China Normal University) have built a magneto-optical trap (MOT) for yttrium oxide (YO) molecules. The two-dimensional MOT uses three lasers and carefully adjusted magnetic fields to partially confine, concentrate, and cool the YO molecules to transverse temperatures of ~2 mK. It is the first device of its kind to successfully laser cool and confine ordinary molecules found in nature.

The Lehnert group has come up with a clever way to transport and store quantum information. Research associate Tauno Palomaki, graduate student Jennifer Harlow, NIST colleagues Jon Teufel and Ray Simmonds, and Fellow Konrad Lehnert have encoded a quantum state onto an electric circuit and figured out how to transport the information from the circuit into a tiny mechanical drum, where is stored. Palomaki and his colleagues can retrieve the information by reconverting it into an electrical signal.

The Ye and Bohn groups have made a major advance in the quest to prepare “real-world” molecules at ultracold temperatures. As recently reported in Nature, graduate students Ben Stuhl and Mark Yeo, research associate Matt Hummon, and Fellow Jun Ye succeeded in cooling hydroxyl radical molecules (^*OH) down to temperatures of no more than five thousandths of a degree above absolute zero (5mK).

When the Thompson group first demonstrated its innovative “superradiant” laser the team noticed that sometimes the amount of light emitted by the laser would fluctuate up and down.  The researchers wondered what was causing these fluctuations. They were especially concerned that whatever it was could also be a problem in future lasers based on the same principles.

The Nesbitt group has figured out the central role of “plasmon resonances” in light-induced emission of electrons from gold or silver nanoparticles. Plasmons are rapid-fire electron oscillations of freely moving (conduction) electrons in metals. They are caused by light of just the “right frequency.”

The world’s most stable optical atomic clock resides in the Ye lab in the basement of JILA’s S-Wing. The strontium-(Sr-)lattice clock is so stable that its frequency measurements don’t vary by more than 1 part in 100 quadrillion (1 x 10^-17) over a time period of 1000 seconds, or 17 minutes.

Most scientists think it is really hard to correlate, or entangle, the quantum spin states of many particles in an ultracold gas of fermions. Fermions are particles like electrons (and some atoms and molecules) whose quantum spin states prevent them from occupying the same lowest-energy state and forming a Bose-Einstein condensate. Entanglement means that two or more particles interact and retain a connection. Once particles are entangled, if something changes in one of them, all linked partners respond.

The Regal group recently completed a nifty feat that had never been done before: The researchers grabbed onto a single trapped rubidium atom (⁸⁷Rb) and placed it in its quantum ground state. This experiment has identified an important source of cold atoms that can be arbitrarily manipulated for investigations of quantum simulations and quantum logic gates in future high-speed computers.

Members of the Jin group found a way to measure for the first time the a type of abstract “surface” in a gas of ultracold atoms that had been predicted in 1926 but not previously observed. Jin and her colleagues are leading researchers in the field of ultracold Fermi gases made up of thousands to millions of fermions.

Researchers from a German national laboratory, the Physikalisch-Technische Bundesanstalt (PTB) have collaborated with Fellow Jun Ye, Visiting Fellow Lisheng Chen (Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences), and graduate student Mike Martin to come up with a clever approach to reducing heat-related “noise” in interferometers. 

Fellow Cindy Regal,  recent JILA grad Matthew Squires (Anderson group, Ph.D. 2008),  former postdoc Wen Li (Kapteyn/Murnane group), and JILA grad Ian Coddington (Cornell group, Ph. D. 2004) have received prestigeous Presidential Early Career Awards for Scientists and Engineers, according to a White House press release issued July 23. Each award is for $1 million over 5 years.

Fellow Ana Maria Rey is Woman Physicist of the Month for June. Rey is  theorist working on many complicated problems in Atomic, Molecular, and Optical (AMO) Physics.  She is well known for her collaborations at JILA with experimentalists Deborah Jin and Jun Ye as well as theorist Murray Holland, CU theorists Victor Guarie and Michael Hermele, and physicists at institutions in the United States and abroad.

News Flash!  The Rey group has discovered another good reason for using alkaline-earth atoms, such as strontium (Sr) or Ytterbium (Yb), in experimental quantum simulators. Quantum simulators are systems that mimic interesting materials or mathematical models in a very controlled way. The new reason for using alkaline earth atoms in such systems comes from the fact that their nuclei come in as many as 10 different magnetic flavors, i.e., their spins can be in 10 different quantum states.

The Thompson group, with theory help from the Holland group, recently demonstrated a superradiant laser that escapes the “echo chamber” problem that limits the best lasers. To understand this problem, imagine an opera singer practicing in an echo chamber. The singer hears his own voice echo from the walls of the room. He constantly adjusts his pitch to match that of his echo from some time before. But, if the walls of the room vibrate, then the singer’s echo will be shifted in pitch after bouncing off of the walls. As a result, if the singer initially started singing an A, he may eventually end up singing a B flat, or a G sharp, or any other random note — spoiling a perfectly good night at the opera.