1. The central picture is a honeycomb lattice toric code model. 2. e and m particles braid around each other on the lattice (should consider the strings as string operators). One can also view the e and m bound state as a fermion, which is self-twisted. 3. One may also imagine the strings as morning clouds (red) surrounding the Colorado mountain (blue) top. 4. The theme and the year of our summer school wrap around in a circle. In between, the Yang-Baxter equation is hidden in the braids. Toric Code Model designed by Yizhuang You
Design 2
The first is inspired by the shape of mountains nearby (South Boulder Peak and Bear Peak), which can also be viewed as the valence band of some material. The surface states can be on the other hand viewed as hiking trails. Colorado mountain TI designed by Linda Ye
Design 3
A second one is a quote from Ari's class yesterday, where he uses cheese cake and brownie to talk about entanglement. Entanglement designed by Linda Ye
Design 4
The ‘hourglass fermion’ is curiously movable but unremovable from the surface of KHgSb. This exotic fermion hangs over the valence bands of KHgSb, which are submerged in the Fermi sea. The fermion's irremovability follows from a spatial symmetry that combines a reflection with a translation. This image is partially inspired by the opening scene in Ayn Rand's Fountainhead, which describes a mountain perfectly reflected on the lake surface. The analogy, mountain -> valence band, lake -> Fermi sea, reflection -> glide reflection. I thought the analogy was appropriate for Boulder. Designed by Aris Alexandradinata
Design 5
The ‘hourglass fermion’ is curiously movable but unremovable from the surface of KHgSb. We demonstrate this robustness by plotting its energy-momentum relationship under various surface deformations. Its irremovability reflects that certain physical properties are completely, topologically immune to perturbations. Designed by Aris Alexadradinata
Design 6
The ‘hourglass fermion’ is curiously movable but unremovable. Its energy is plotted as a function of momentum, bands connect one hourglass to the next in an unbreakable zigzag pattern. This exotic fermion is materialized by KHgSb, as depicted by an atomic background. Designed by Aris Alexandradinata
For further information for designs 4-6:
If you are curious about the theory and material proposal behind these images, you can find them here:
It's based on the pentagon equation. The different fusion diagrams are represented by the branches and the darkened roots, and connected by arrows. The slogan "be consistent" is a reference to the fact that the pentagon equation is one of the consistency equations (for the $F$-symbol) in the description of topological orders in terms of tensor categories. Designed by Zhaoxi (Charles) Xiong and Ryan Thorngren
It's based on the pentagon equation. The different fusion diagrams are represented by the branches and the darkened roots, and connected by arrows. The slogan "be consistent" is a reference to the fact that the pentagon equation is one of the consistency equations (for the $F$-symbol) in the description of topological orders in terms of tensor categories. Designed by Zhaoxi (Charles) Xiong and Ryan Thorngren
![Pentagon Equation designed by Zhaoxi (Charles) Xiong and Ryan Thorngren](/sites/default/files/images/tee-shirts-07.jpg "It's based on the pentagon equation. The different fusion diagrams are represented by the branches and the darkened roots, and connected by arrows. The slogan "be consistent" is a reference to the fact that the pentagon equation is one of the consistency equations (for the $F$-symbol) in the description of topological orders in terms of tensor categories. Designed by Zhaoxi (Charles) Xiong and Ryan Thorngren")
![Pentagon Consistancy Equation designed by Zhaoxi (Charles) Xiong and Ryan Thorngren](/sites/default/files/images/tee-shirts-07b.jpg "It's based on the pentagon equation. The different fusion diagrams are represented by the branches and the darkened roots, and connected by arrows. The slogan "be consistent" is a reference to the fact that the pentagon equation is one of the consistency equations (for the $F$-symbol) in the description of topological orders in terms of tensor categories. Designed by Zhaoxi (Charles) Xiong and Ryan Thorngren")