Synopsis

Solving Many-Body Problems with a Quantum Microscope

Physics 10, s65
A microscope that images the momenta of atoms in a Bose-Einstein condensate could solve quantum many-body problems.
S. S. Hodgman et al., Phys. Rev. Lett. (2017)

Elucidating the quantum behavior of large ensembles of interacting particles typically requires knowledge of the system’s many-body wave function. When the ensemble contains a few million atoms—typical for Bose-Einstein Condensates (BECs)—this is no mean feat. Sean Hodgman, from the Australian National University, and colleagues have now demonstrated a way to tackle this so-called quantum many-body problem that doesn’t require the wave function to be known. Their method instead determines all the parameters needed to characterize the system from measurements of the correlations between the momenta of individual atoms in the ensemble.

The researchers’ method involves recording the momenta of scattered atoms after two ensembles of BEC atoms are collided with one another. The atoms’ momenta obtained from such recordings are then used to calculate the correlations between all pairs and triplets of atoms in the scattered atom cloud. According to the group’s theoretical derivations and experimental measurements, these correlations are sufficient to solve the many-body problem for this system.

The team demonstrated their technique by smashing together two BECs, collectively containing one million helium atoms. Recording each atom’s position at various times after the collision, they reconstructed the atoms’ momenta and calculated the momentum correlation functions up to third order (three-atom correlations). Since the setup can map the atoms’ momenta in three dimensions, it can be regarded as a quantum many-body momentum microscope. Such a microscope could make it easier to study important many-body effects, including many-body localization phenomena and glassy behavior in highly disordered systems.

This research is published in Physical Review Letters.

–Katherine Wright

Katherine Wright is a Contributing Editor for Physics.


Subject Areas

Quantum PhysicsAtomic and Molecular Physics

Related Articles

Hidden Behavior of Quantum Quasicrystals
Quantum Physics

Hidden Behavior of Quantum Quasicrystals

A new theory unveils the exotic low-energy excitations of quasicrystals formed of quantum particles. Read More »

Microwaves Can Suppress Chemical Reactions
Chemical Physics

Microwaves Can Suppress Chemical Reactions

The heating effect of microwaves has long been used to accelerate reactions. A new experiment shows that microwaves can also excite molecules into a less reactive state. Read More »

Gauging the Temperature Sensitivity of a Nuclear Clock
Atomic and Molecular Physics

Gauging the Temperature Sensitivity of a Nuclear Clock

Researchers have characterized the temperature-induced frequency shifts of a thorium-229 nuclear transition—an important step in establishing thorium clocks as next-generation frequency standards. Read More »

More Articles