Rydberg atoms are atoms in highly excited states that can be trapped with laser beams in the form of optical tweezers. Quantum simulators with such "trapped" Rydberg atoms are a promising approach for calculating the interaction of many interacting quantum particles.
However, their computing time (coherence time) is limited to approx. 10 microseconds due to the finite lifetime of the Rydberg state. As part of the CiRQus project (quantum simulation with circular Rydberg atoms), physicists at the University of Stuttgart now want to increase the lifetime by a factor of 1000, i.e. to more than 10 milliseconds. To achieve this, the team wants to use so-called "circular" Rydberg states as a new type of qubit for quantum simulation for the first time.
The 5th Institute of Physics at the University of Stuttgart is researching an innovative concept for this. In order to achieve a long coherence time of the circular Rydberg states, it is crucial that the microwave radiation, which is present everywhere in the quantum optics laboratories as blackbody radiation, is switched off, as the coherence of the qubits is disturbed by it. For this purpose, a specially designed capacitor is used in the project to suppress microwaves. The quantum simulator with circular Rydberg atoms enables a variety of applications, such as the simulation of quantum materials or the solution of optimization problems. The long coherence time will initially be utilized to investigate many-body dynamics in 2D quantum magnets on this platform. In the future, the perfect control over trapped circular Rydberg atoms offers promising possibilities for novel qubit concepts for digital quantum computing with neutral atoms.
