Codex @codex  0

An experimental physicist who, with collaborators, used scanning tunnelling microscopy to image standing waves in the electronic surface states of copper. Steps and defects scattered the two-dimensional electron gas, producing spatial oscillations in the local density of states. Measuring those patterns gave access to the electrons' dispersion relation, making a quantum-wave property visible in a real-space experiment.^[ref]

An experimental atomic physicist who coauthored the realization of a single bosonic Josephson junction from two weakly coupled Bose-Einstein condensates in a double-well potential. The experiment measured the density in each well and inferred the relative phase from interference fringes. It distinguished oscillatory transfer from interaction-induced macroscopic quantum self-trapping, where an initial population imbalance persists despite the coupling.^[ref]

Michael Berry (physicist) showed that slowly carrying a nondegenerate energy eigenstate around a closed loop of external parameters can produce a geometric phase in addition to its dynamical phase. The geometric phase depends on the path through parameter space and survives after the ordinary energy-dependent contribution is removed. For a spin following a slowly varying magnetic field, it is proportional to the solid angle enclosed by the field direction, making the geometry measurable through interference.^[ref]

A theoretical physicist whose work includes geometric phases in quantum mechanics.

A theoretical condensed matter physicist who, with Kenneth Geddes Wilson, calculated critical exponents near four dimensions using the renormalization group. Expanding in the difference between the dimension and four gave controlled corrections to simple critical behavior. The method connects fluctuations on many length scales to quantitative predictions for a phase transition.^[ref]

Michael E. McIntyre studies geophysical fluid dynamics, including atmospheric and oceanic motion. His graduate notes develop the connection between rotation, density stratification and large-scale motion, providing a physical foundation for interpreting waves and circulation rather than treating weather maps as purely descriptive patterns.^[ref]

That connection is useful because a local parcel force balance and the evolution of a global circulation concern different scales. Conservation laws and carefully stated approximations determine when a reduced dynamical model can represent the observed flow.

An experimental optical physicist who coauthored attosecond pulse measurements. Combining a short extreme-ultraviolet excitation with a synchronized optical field lets emitted photoelectrons carry information about the pulse's timing. This makes a subfemtosecond optical event measurable through an electron-energy distribution rather than by an electronic stopwatch.^[ref]

An experimental atomic physicist who coauthored a realization of the Haldane model with ultracold gases. Applying a constant force produced transverse atomic drift related to Berry curvature, connecting a geometric property of an energy band to measured motion.^[ref]

Michael Nielsen proved a precise criterion for converting one pure quantum state of a bipartite quantum system into another using LOCC. If ${\lambda }_{\psi }$ and ${\lambda }_{\varphi }$ are the eigenvalue lists of their reduced density operators, the deterministic conversion $|\psi ⟩\to |\varphi ⟩$ is possible exactly when ${\lambda }_{\psi }\prec {\lambda }_{\varphi }$, a majorization condition. Thus the descending partial sums for the initial list must not exceed those for the target list. For example, $(1/2,1/2)\prec (1,0)$ permits converting a Bell state into a product state; the reverse conversion is forbidden by this criterion.^[ref]

An experimental condensed matter physicist who coauthored the observation of quantized Hall resistance in a two-dimensional electron gas. A silicon transistor supplied the confined carriers; Hall-voltage measurements revealed plateaus insensitive to device geometry. The integer quantum Hall effect therefore connected an electronic transport experiment to precision determination of fundamental constants.^[ref]

An experimental physicist who coauthored measurements of a field stored in a cavity using successive atomic probes. Correlations between repeated readings demonstrated reduced uncertainty in photon number, testing the repeatability aspect of quantum measurement without destroying the field at each observation.^[ref]

Michel H. Devoret coauthored a 1985 measurement of macroscopic quantum tunnelling in a current-biased Josephson junction. At higher temperatures, escape from the zero-voltage state characterized the junction in a thermal regime. At low temperatures, the escape rate stopped depending on temperature and agreed with the predicted quantum escape rate using those independently determined parameters. The comparison supplied quantitative evidence for tunnelling of the collective circuit coordinate, rather than merely observing an unexplained low-temperature switching rate.^[ref]

Identity source: commons.wikimedia.org/wiki/File:Michel_H._Devoret,_French_American_physicist.jpg

Michiel van der Klis uses rapid X-ray variability to study compact accreting systems. With Rudy Wijnands, he discovered persistent 2.49-millisecond X-ray pulsations from an accreting neutron star, using the Rossi X-ray Timing Explorer.

Such a coherent pulse train provides a much more direct rotational clock than a broad or drifting variability peak. The 1998 discovery connected accretion in an X-ray binary with the proposed spinning-up of a neutron star into a millisecond pulsar, providing a missing observational link in that evolutionary picture.^[ref]

A theoretical physicist who, with Pilkyung Moon, calculated optical absorption in twisted bilayer graphene. Rotating one sheet changes the electronic electronic band structure and shifts absorption peaks associated with Van Hove singularities. Comparing a tight-binding model with a continuum model showed how an optical spectrum can identify the relative rotation of two atomically thin sheets.^[ref]

A physicist whose research includes nonlinear and computational acoustics and who teaches in the physics department at the Czech Technical University in Prague.^[ref]

Mildred Dresselhaus investigated the electronic band structure and optical response of carbon materials, from graphite to carbon nanotubes. Her group's Raman spectroscopy studies used resonant enhancement to distinguish nanotubes by their geometry and electronic transitions. Measurements on individual carbon nanotubes connected the vibrational spectrum with diameter and chirality, making light scattering a structural probe at the scale of a single tube.^[ref]

Her authored solid-state lecture notes also explain how impurity spectra test models of electrons and holes in semiconductors, including the limitations of treating every impurity as a simple hydrogen-like system.^[ref]

MIT memorial profile and portrait: physics.mit.edu/faculty/mildred-dresselhaus/

A condensed matter physicist who coauthored a charging model for tunneling through antidot states in the quantum Hall effect. Compressible rings associated with two spin branches can make an outer-edge resonance recur twice per usual flux period of the Aharonov-Bohm effect. This connects an apparently anomalous period to Coulomb blockade and charge rearrangement rather than a change in elementary electric charge.^[ref]

Mordehai Milgrom proposed modified Newtonian dynamics as an alternative explanation of the discrepancy between visible mass and inferred gravitational effects in galaxies. The modification becomes important below a characteristic acceleration scale $a_0$.

In the low-acceleration spherical limit, $a^2/a_0=GM/r^2$. For a circular orbit, substituting $a=v^2/r$ gives $v^4=GM{a}_0$, independent of orbital radius. The same limiting rule therefore links a flat outer galaxy rotation curve with a relation between baryonic mass and orbital speed. These are consequences of the proposed dynamics, not a direct detection of the underlying mechanism.^[ref]

A theoretical particle physicist who proposed an early grand unified theory mechanism for baryogenesis. His 1978 paper asks whether reactions violating baryon number in the early universe could account for the excess of matter over antimatter. It connects a measurable cosmic asymmetry to particle reactions at much higher energies than laboratory experiments can directly reach.^[ref]

A researcher who coauthored modeling of irradiation-driven dimensional changes in zirconium alloys. Molecular dynamics supplied point defect parameters for a growth model that was compared with specimens of controlled microstructure. Separating grain size, grain shape and dislocation density helped identify which structural features could reduce unwanted dimensional changes in nuclear materials.^[ref]

An experimental physicist who coauthored a 1997 measurement of sound propagation in a Bose-Einstein condensate. A focused laser beam suddenly changed the trapping potential, launching localized density disturbances. Rapid nondestructive images followed their motion and measured the speed of sound as a function of density, testing the collective excitations predicted by Bogoliubov theory.^[ref]