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Physics education researchers from the ���� and the University of Maine recently showed that students troubleshooting a malfunctioning electric circuit successfully tackled the problem by using models of how the circuit ought to work. The researchers confirmed this approach by analyzing videotapes of eight pairs of students talking aloud about their efforts to diagnose and repair a malfunctioning electric circuit. The circuits had not just one, but two problems. Both problems had to be corrected for the circuit to work properly.

Newly minted Ph.D. Ming-Guang Hu and his colleagues in the Jin and Cornell groups recently investigated immersing an impurity in a quantum bath consisting of a Bose-Einstein condensate, or BEC. The researchers expected the strong impurity-boson interactions to “dress” the impurity, i.e., cause it to get bigger and heavier. In the experiment, dressing the impurity resulted in it becoming a quasi particle called a Bose polaron.

Bob Peterson and his colleagues in the Lehnert-Regal lab recently set out to try something that had never been done before: use laser cooling to systematically reduce the temperature of a tiny drum made of silicon nitride as low as allowed by the laws of quantum mechanics. Although laser cooling has become commonplace for atoms, researchers have only recently used lasers to cool tiny silicon nitride drums, stretched over a silicon frame, to their quantum ground state. Peterson and his team decided to see just how cold their drum could get via laser cooling.

The Kapteyn/Murnane group has measured how long it takes an electron born into an excited state inside a piece of nickel to escape from its birthplace. The electron’s escape is related to the structure of the metal. The escape is the fastest material process that has been measured before in the laboratory––on a time scale of a few hundred attoseconds, or 10-18 s. This groundbreaking experiment was reported online in Scienceon June 2, 2016. Also in Science on July 1, 2016, Uwe Bovensiepen and Manuel Ligges offered important insights into the unusual significance of this work.

The Ye group just solved a major problem for using molecular fingerprinting techniques to identify large, complex molecules: The researchers used an infrared (IR) frequency comb laser to identify four different large or complicated molecules. The IR laser-light absorption technique worked well for the first time with these larger molecules because the group combined it with buffer gas cooling, which precooled their samples to just a few degrees above absolute zero.

Move over, single-atom laser cooling! The Holland theory group has just come up with a stunning idea for a new kind of laser cooling for use with ensembles of atoms that all “talk” to each other. In other words, the theory looks at laser cooling not from the perspective of cooling a single atom, but rather from the perspective of many atoms working together to rapidly cool themselves to a miniscule fraction of a degree above absolute zero.

The old JILA molecule factory (built in 2002) produced the world’s first ultracold polar molecules [potassium-rubidium (KRb)] in 2008. The old factory has been used since then for ultracold chemistry investigations and studies of the quantum behavior of ultracold molecules and the atoms that form them. The Jin-Ye group, which runs the molecule factory, is now wrapping up operations in the old factory with experiments designed to improve operations in the ultramodern factory, which is close to completion.

The Ye and Rey groups have discovered the strange rules of quantum baseball in which strontium (Sr) atoms are the players, and photons of light are the balls. The balls control the players by not only getting the atoms excited, but also working together. The players coordinate throwing and catching the balls. While this is going on, the balls can change the state of the players! Sometimes the balls even escape the quantum baseball game altogether and land on detectors in the laboratory.

Cong Chen and his colleagues in the Kapteyn/Murnane group have generated one of the most complex coherent light fields ever produced using attosecond (10-18 s) pulses of circularly polarized extreme ultraviolet (EUV) light. (The circularly polarized EUV light is shown as rotating blue sphere on the left of the picture. The complex coherent light field is illustrated with the teal, lilac, and purple structures along the driving laser beam (wide red line).

The Regal and Rey groups have come up with a novel way to generate and propagate quantum entanglement [1], a key feature required for quantum computing. Quantum computing requires that bits of information called qubits be moved from one location to another, be available to interact in prescribed ways, and then be isolated for storage or subsequent interactions. The group showed that single neutral atoms carried in tiny traps called optical tweezers may be a promising technology for the job!