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In a new paper published in Nano Letters, JILA Fellow Markus Raschke and graduate student Thomas Gray describe how they developed a way to image and visualize how surface molecules couple and interact with quantum precision. The team believes that their nanospectroscopy method could be used for molecular engineering to develop better molecular surfaces, with controlled properties for molecular electronic, photonic, or biomedical applications.

The Bose-Einstein Condensate (BEC) has been studied for decades, ever since its prediction by scientists Satyandra Nath Bose and Albert Einstein nearly 100 years ago. The BEC is a gas of atoms cooled to almost absolute zero. At low enough temperatures, quantum mechanics allows the locations of the atoms in the BEC to be uncertain to the extent that they can’t be located individually in the gas. The BEC has a special history with JILA, as it was at JILA that the first gaseous condensate was produced in 1995 by JILA Fellows Eric Cornell (NIST) and Carl Wieman (University of Colorado Boulder). Since 2005, research on dipolar BEC has continued, using different theories to describe the droplet’s interactions. In a paper recently published in Physical Review A, first author, and graduate student, Eli Halperin and JILA fellow John Bohn theorize a way to study the BEC using a hyperspherical approach. While the name may sound intimidating, the hyperspherical approach is simply a systematic way to look at a many-body problem. The many body problem refers to a large category of problems regarding microscopic systems with interacting particles. Bohn and Halperin applied this approach to a dipolar BEC specifically.

Two new papers from the Murnane and Kapteyn group are changing the way heat transport is viewed on a nanoscale, and explain the group’s surprising finding that nanoscale heat transport can be far more efficient than originally thought. One of these papers, published in the Proceedings of the National Academy of Sciences (PNAS), explains heat transport for the tiniest of hotspots, with sizes <100 nm. The other, published in American Chemical Society Nano (ACS Nano), presents a theory that is applicable to larger arrays of hotspots. Both papers postulate theories that can fully explain the surprising data collected by the team of researchers, showing that heat transport on scale lengths relevant to a wide range of nanotechnologies is more efficient than originally thought.

Atomic clocks have been heavily studied by physicists for decades. The way these clocks work is by having atoms, such as rubidium or cesium, that are "ticking" (that is, oscillating) between two quantum states. As such, atomic clocks are extremely precise, but can be fragile to shaking or other perturbations, like temperature fluctuations. Additionally, these clocks need a special laser to probe the clock. Both factors can make atomic clocks imprecise, difficult to study, and expensive to make. A team of physicists are proposing a new type of laser that could change the future path of atomic clocks. In this team, JILA Fellow Murray Holland and Research Associate Simon Jäger theorized a new type of laser system in a paper recently published in Physical Review Letters.

For laser science, one major goal is to achieve full control over the spatial, temporal and polarization properties of light, and to learn how to precisely manipulate these properties. A property of light is called the Orbital Angular Momentum (OAM), that depends on the spatial distribution of the phase (or crests) of a doughnut-shaped light beam. More recently, a new variant of OAM was discovered - called the spatial-temporal OAM (ST-OAM), with much more elusive properties, since the phase/crests of light evolve both temporally and spatially. In a collaboration led by senior scientist Dr. Chen-Ting Liao, working with graduate student Guan Gui and Nathan Brooks and JILA Fellows Margaret Murnane and Henry Kapteyn, the team explored how such beams change after propagating through nonlinear crystals that can change their color. The team published theri results in Nature Photonics.

The basic question of how strands of nucleic acids (DNA and RNA) fold and hybridize has been studied thoroughly by biophysicists around the globe. In particular, there can be unexpected challenges in obtaining accurate kinetic data when studying the physics of how DNA and RNA fold and unfold at the single molecule level. One problem comes from temporal camera blur, as the cameras used to capture single photons emitted by these molecules do so in a finite time window that can blur the image and thereby skew the kinetics. In a paper published in the Journal of Physical Chemistry B, JILA Fellow David Nesbitt, and first author David Nicholson, propose an extremely simple yet broadly effective way to overcome this camera blur.

Physicists at the National Institute of Standards and Technology (NIST) have linked together, or “entangled,” the mechanical motion and electronic properties of a tiny blue crystal, giving it a quantum edge in measuring electric fields with record sensitivity that may enhance understanding of the universe.

Many physicists use lasers to study quantum mechanics, atomic and molecular physics and nanophysics. While these lasers can be helpful in the research process, there are certain constraints for the researcher. According to JILA Fellow Andreas Becker: "For certain wavelengths of these laser pulses, such as deep ultraviolet, you may not know, or not be able to measure, the temporal profile." The temporal profile of a laser pulse is, however, important for researchers when analyzing data. "A lot of people cannot fully analyze their data, because they don't know the details of the pulse that was used to produce the data," said graduate student Spencer Walker. As a way to research this constraint, the Becker and Jaron-Becker laboratories collaborated to publish a paper in Optics Letters, suggesting a possible solution.

The process of creating spin-polarized electrons has been studied for some time but continues to surprise physicists. These types of electrons have their spin aligned in a specific direction. The probability of creating a spin-polarized electron from an atom tends to be rather small except in some very specific situations. Yet, in a new paper published in Physical Review A, JILA graduate student Spencer Walker, former graduate student Joel Venzke, and former undergraduate student Lucas Kolanz in the Becker Lab theorized a new way towards enhancing this probability through the use of ultrashort laser pulses and an electron’s so-called doorway states. These doorway states are excited states of an electron in an atom that is closest to its lowest energy state, the ground state.

In a new paper published in Physical Review Letters, JILA and NIST Fellows Eric Cornell, Jun Ye, and Konrad Lehnert developed a method for measuring a potential dark matter candidate, known as an axion-like particle. Axion-like particles are a potential class of dark matter particle which could explain some aspects of galactic structure. This work is also a result of collaboration with Victor Flambaum who is a leading theorist studying possible violations of fundamental symmetries.