ΔBz oscillations.: (a) The pulse sequence used to estimate ΔBz. (b) Using nuclear feedback, ΔBz oscillations decay in a coherence time due to residual slow fluctuations in ΔBz. (c) The Ramsey sequence used to operate the S-T*2 ≈ qubit in the rotating frame. (d) The Ramsey contrast (blue dots) decays in a characteristic time (solid line fit ) similar to the oscillations in b due to the same residual slow fluctuations in ΔBz. (e) The Rabi pulse sequence used to drive the qubit in the rotating frame.
The Harvard Physics Teaching Lab is hosting a section of a course taught by Neil Gershenfeld (MIT) and offered jointly at MIT and Harvard, "How to Make (Almost) Anything." The Harvard section is comprised of five women and eleven men from across the campus, including students and staff from Physics, SEAS, GSD, and other departments.
Phase diagram of exciton topological phases: a,b, Diagrams for the upper and lower energy exciton Hamiltonians (v = L, U), respectively. Light and dark blue regions denote topologically non-trivial phases with Chern number equal to − 1 and 1, exhibiting edge states with anticlockwise and clockwise exciton currents, respectively. Switching the direction of the magnetic field to Bz
Aquatic swimming: a,The organisms considered in the article span eight orders of magnitude in Reynolds number and encompass larvae (from mayfly to zebrafish), fish (from goldfish, to stingrays and sharks), amphibians (tadpoles), reptiles (alligators), marine birds (penguins) and large mammals (from manatees and dolphins to belugas and blue whales). Blue fish sketch by Margherita Gazzola. b, Swimmer of length L is propelled forward with velocity U by pushing a bolus of water14, 20, 24 through body undulations characterized by tail beat amplitude A and frequency ω.
Known empirical scaling laws for gray-matter volume and thickness are mapped on a g2 vs. R/T diagram. Corresponding simulations for spherical brain configurations, with images shown at a few points, show that the surface remains smooth for the smallest brains, but becomes increasingly folded as the brain size increases. [From T. Tallinen, J.Y. Chung, J.S. Biggins, and L. Mahadevan, "Gyrification from constrained cortical expansion," PNAS 2014 | doi:10.1073/pnas.1406015111]