Abbamonte Group

The M-EELS experiment is down for six weeks as the ESCO project to rebuild the HVAC system for the entire MRL building moves to our floor. The whole instrument is now encased in a giant plywood box to protect it from dust and mishaps. We hope to be recommissioning the instrument in the middle of March. No new science will happen until early May.

We just published a paper finally demonstrating that TiSe₂ contains a Bose condensate of excitons. The experimental signature is a soft plasmon that falls to zero frequency at T_c. Bert Halperin and Maurice Rice nicknamed this phase “excitonium” in their  1968 Rev. Mod. Phys. paper to emphasize the physical picture of an exciton condensate as an electronic crystal. This discovery, which we believe should be viewed as a landmark in our field, was done using our new M-EELS technique (see Sean’s paper, below).

The media frenzy over this discovery has been unreal, surpassing our wildest expectations. Some of the better written articles may be found in Newsweek, The Independent, and the The Daily Mail. Here is a polished video on YouTube.

Here’s a link to the article in Science.

Our low-temperature crystallography instrument has a new home. It now lives in a dedicated space in 117 MRL, where it will be used by many research groups for decades to come. Stella Sun and Sangjun Lee did a great job moving the equipment, and thanks go to Youli Li for helping with the alignment and calibration.

We just finished our first Free Electron Laser experiment, using the SXR endstation during Run 15 of the Linac Coherent Light Source. The goal was to study the collective modes of the stripe phase in La_2-xBa_xCuO₄.

SLAC Facebook post here.

After 2.5 years of refereeing, Sean’s M-EELS paper was finally published in the open-access journal SciPost. This paper explains the reasons for developing the M-EELS technique and how it works.

Read it here.