Synopsis: Superposed in a Crystal

Spin-dependent forces create quantum superpositions of different structures of a trapped ion crystal.
Synopsis figure
J. D. Baltrusch et al., Phys. Rev. A (2011)

In quantum mechanics, a system with distinct eigenstates can exist in a superposition of two or more states with specific probability amplitudes. The creation and manipulation of these superpositions is central to quantum computing. Efforts to experimentally realize quantum superpositions of macroscopic objects that are larger than an electron or a photon have generally focused on controlling their quantum dynamics and their interaction with the environment. Strings of trapped ions, an interesting example of many-body objects that can behave quantum mechanically, have attracted attention due to their remarkable contribution to quantum technologies, such as their use in the realization of quantum simulators and quantum teleportation protocols.

In an article in Physical Review A, Jens Baltrusch at Saarland University, Germany, and his colleagues report theoretical work on the dynamics of two different structures—linear and zigzag—of a trapped ion crystal. Starting out with a chain of ions at rest in a regime close to its structural phase transition, they excite—with spin-dependent trapping—a particular ion of the crystal into a superposition of metastable electronic states. Coulomb forces then modify the motions of the other ions in relation to the state of the chosen one, producing a state in which all the ions are entangled. This state is manifested as a superposition of different crystalline structures—a so-called cat state—and, according to the authors, should be observable with interferometry. – Jihane Mimih


Features

More Features »

Announcements

More Announcements »

Subject Areas

Quantum InformationMesoscopicsQuantum Physics

Previous Synopsis

Next Synopsis

Superconductivity

Pnictide Gap Symmetry

Read More »

Related Articles

Viewpoint: Record Distance for Quantum Cryptography
Optics

Viewpoint: Record Distance for Quantum Cryptography

An optical-fiber-based quantum cryptography scheme works over a record distance of 421 km and at much faster rates than previous long-distance demonstrations. Read More »

Viewpoint: Counting the Quanta of Sound
Acoustics

Viewpoint: Counting the Quanta of Sound

Two teams demonstrate that they can count the number of quantized vibrations, or phonons, in cold mechanical oscillators by measuring the energy in the vibrations. Read More »

Focus: Entangled Photons Sneak through Hole Unscathed
Nanophysics

Focus: Entangled Photons Sneak through Hole Unscathed

The fragile quantum state of a pair of entangled photons can be protected when the photons pass through a nanoscale hole, which may be useful in future light-based computing. Read More »

More Articles