Hao Li

In 1963, a Tanzanian schoolboy named Erasto Mpemba noticed that hot ice cream freezes faster than cold. That paradox, named after him, long remained a subject of debate in classical thermodynamics. Now the quantum world offers its own version: a state with more strongly broken symmetry can recover it faster than a less broken one.

Hydrogen is a champion in energy per kilogram, but storing it is a hassle. As a gas, it takes up a huge volume, and if you compress it or cool it to a liquid, you need heavy tanks and lots of energy. There's a third way: some solid materials absorb hydrogen like a sponge soaks up water and hold it within. Heat it up, hydrogen comes out; cool it down, it gets absorbed back.

A regular computer amplifies a signal like a megaphone amplifies a voice. But a megaphone doesn't work for a quantum computer: it distorts the whisper too much. And the whisper here is the signal from qubits, the cells of quantum memory. The signal is so weak that any extra noise drowns it out.

A squad of soldiers marches across a parade ground. As long as everyone keeps in step, the movement remains sharp and coordinated. But if someone falls out of line, the order is lost. In the microworld, electrons play the role of such a squad: when their oscillations are synchronized, the substance emits a narrow, sharp line.

A solid electrolyte is not just a crystal lattice: it’s a bustling metropolis for ions. Each act of conduction resembles a trip through the city: there are wide highways with low energy barriers, gridlocks in bottlenecks, and tricky detours where an ion can get stuck.

Water in a glass looks continuous, but it's actually a dance of trillions of molecules constantly breaking and forming bonds. Seeing this dance in full detail was previously impossible: accurate calculations that account for the quantum properties of electrons could only handle tiny droplets of a few hundred atoms. The new model UBio-MolFM changes the game.

It is easier to turn a jar lid by gripping its edge than its center. Layered crystals such as graphite behave similarly when one layer is twisted relative to another: the resistance arises not from the whole contact area but only from its rim.