PRL A new way to manipulate Rydberg quantum states

Oscillating the optical lattice of Rydberg atoms at the right frequency causes the atoms to undergo an electron jump - which is useful for quantum processing techniques.

Rydberg atoms are those with highly excited electrons, which can be used for quantum computing and quantum simulations due to favorable properties such as long lifetimes. To realize these applications, researchers want to trap atoms in a one-dimensional (1D) lattice and manipulate the quantum state of each atom with a laser. However, laser-based "quantum state jump-driven methods" have had difficulty realizing odd-parity transitions, which are necessary for some types of quantum information processing.

Now, researchers at the University of Michigan, Ann Arbor, have developed a method that induces simultaneous, parity-checked Rydberg transitions in atoms trapped in a one-dimensional lattice, making the system more suitable for quantum information processing.

The paper, titled "Driving Alkali Rydberg Transitions with a Phase-Modulated Optical Lattice," was published July 11 in Physical Review Letters.

For their demonstration, Ryan Cardman and Georg Raithel captured Rydberg atoms in a one-dimensional optical lattice. They added a third laser beam and changed its phase to "slide" the lattice back and forth in the direction of the laser. When they changed the frequency of oscillation, they measured the quantum states of the Rydberg atoms excited in the lattice.

Cardman and Raithel found that the atoms in the lattice could switch between Rydberg quantum states when the transition frequency of the excited atoms was an integer multiple of the oscillation frequency. The duo confirmed that the oscillating lattice was the source of the excitation by blocking one of the lattice lasers; and, the spectral lines showing the state switching disappeared.

The resulting measured spectral lines also match the duo's simulations as well as the expected results based on an alternative microwave irradiation method.

Parity check (even-parity spectrum) results.

In the paper, the authors state, "The method paves the way for Rydberg-based simulators, optical Doppler-free high-precision spectroscopy of Rydberg leaps in quantum computers, and spatially selective (SPATIAL SELECTIVE) quantum bit manipulation with micrometer resolution."

Reference link:

[1]https://physics.aps.org/articles/v16/s105

[2]https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.023201