Another step on the journey to quantum computers – Deskarati –
Physicists in Germany are the first to flip individual atomic spins in an optical lattice. The researchers, who are based at the Max Planck Institute for Quantum Optics in Garching, used a combination of laser light and microwaves to address individual rubidium atoms arranged in a state known as a “Mott insulator”. Their method could be used for making quantum computers and also for simulating the behaviour of electrons in solids – especially superconductors.
This newfound ability is just the latest example of the progress that physicists have made in understanding quantum interactions by studying ultracold atoms in optical lattices of crisscrossing laser beams. By adjusting the laser light and applied magnetic fields, scientists can “tune” the interactions between atoms and simulate the behaviour of electrons in crystalline solids. Although an atom in an optical lattice can normally tunnel from one lattice site to a neighbouring site, in a Mott insulator all the sites are occupied, which means that the energy cost of tunnelling is too great and the atoms are frozen in place.
Each of these frozen atoms, however, could make an excellent quantum bit (qubit) in a quantum memory because they are highly isolated from the surrounding environment. And as each atom has a magnetic spin, optical Mott insulators could be used to simulate the effect of spin on electronic properties such as conduction. However, physicists had been unable to adjust the value of individual spins, limiting the usefulness of optical Mott insulators.
Read more here Single spins flipped in optical lattice – physicsworld.com.