Microwave control of Rydberg atom interactions

We investigate the interaction between Rydberg atoms, whose electronic states are dressed by multiple microwave fields. Numerical calculations are used for an exact description of the microwave induced interactions, and employed to benchmark a perturbative treatment that yields simple insights into the involved mechanisms. Based on this theory, we demonstrate that microwave dressing provides a powerful approach to control dipolar as well as van der Waals interactions and even permits us to turn them off entirely. In addition, the proposed scheme also opens up possibilities for engineering dominant three-body interactions.We investigate the interaction between Rydberg atoms, whose electronic states are dressed by multiple microwave fields. Numerical calculations are used for an exact description of the microwave induced interactions, and employed to benchmark a perturbative treatment that yields simple insights into the involved mechanisms. Based on this theory, we demonstrate that microwave dressing provides a powerful approach to control dipolar as well as van der Waals interactions and even permits us to turn them off entirely. In addition, the proposed scheme also opens up possibilities for engineering dominant three-body interactions.

arXiv:1412.4925New Journal of PhysicsDec 15, 201443 citations

Binding Potentials and Interaction Gates between Microwave-Dressed Rydberg Atoms

David Petrosyan, Klaus Mølmer

We demonstrate finite range binding potentials between pairs of Rydberg atoms interacting with each other via attractive and repulsive van der Waals potentials and driven by a microwave field. We show that, using destructive quantum interference to cancel single-atom Rydberg excitation, the Rydberg-dimer states can be selectively and coherently populated from the two-atom ground state. This can be used to realize a two-qubit interaction gate which is not susceptible to mechanical forces between the atoms and is therefore immune to motional decoherence.We demonstrate finite range binding potentials between pairs of Rydberg atoms interacting with each other via attractive and repulsive van der Waals potentials and driven by a microwave field. We show that, using destructive quantum interference to cancel single-atom Rydberg excitation, the Rydberg-dimer states can be selectively and coherently populated from the two-atom ground state. This can be used to realize a two-qubit interaction gate which is not susceptible to mechanical forces between the atoms and is therefore immune to motional decoherence.

arXiv:1404.3365Physical Review LettersSep 19, 201461 citations

Microwave Control of Rydberg Interactions in a Cold-Atom Experiment

Deniz Kurdak

Advances in the coherent control of Rydberg atoms have led to an explosion in their use in a wide range of topics, including quantum computation, simulation, sensing, and networking. More specifically, Rydberg-coupled ensembles of atoms interfaced with a single mode of light have enabled studies of fundamental light-matter interactions at the single-photon level and have emerged as a promising platform to realize scalable quantum networking nodes. In the first part of this thesis, we utilize Rydberg blockade to generate large ensembles that host a single Rydberg excitation and use the collective state as a resource to efficiently generate single photons. We further investigate the shelving of the collective Rydberg excitations to the ground-state manifold, where we observe an order of magnitude increase in the coherence time of the excitation. In the latter half of the thesis, we use near-resonant microwave fields to generate microwave-dressed Rydberg states, where we utilize the degrees of freedom of the microwave field to tune the strength, form, and angular dependence of the dipole-dipole interactions. To this end, we develop a robust and highly tunable microwave polarization control system. We use a set of in-vacuum electrodes as microwave antennas. We measure the microwave polarizations produced by each source at the positions of the atoms using a Rydberg EIT-based polarimetry technique. By characterizing the three imperfect sources, we find the control settings necessary to produce \sigma_-, \pi, and \sigma_+ polarized microwaves with >99 % fidelity. We extend our purification techniques to frequencies away from Rydberg resonances by utilizing an auxiliary microwave field, generating two-photon microwave resonances. The high-fidelity microwave polarizations are used to resonantly admix opposite-parity Rydberg states, generating dressed states with dipole-dipole interactions that are longer range and stronger than the bare van der Waals interactions. To characterize the strength of the interactions, we measure the photon-number statistics of the light generated by the ensemble of atoms. By varying the cloud length relative to the blockade radii, we demonstrate a clear enhancement of the interaction strength due to microwave dressing. Our platform enables further engineering of interactions by exploiting the polarization and frequency degrees of freedom of the microwave fields, opening pathways for new quantum control strategies in many different experimental platforms.Advances in the coherent control of Rydberg atoms have led to an explosion in their use in a wide range of topics, including quantum computation, simulation, sensing, and networking. More specifically, Rydberg-coupled ensembles of atoms interfaced with a single mode of light have enabled studies of fundamental light-matter interactions at the single-photon level and have emerged as a promising platform to realize scalable quantum networking nodes. In the first part of this thesis, we utilize Rydberg blockade to generate large ensembles that host a single Rydberg excitation and use the collective state as a resource to efficiently generate single photons. We further investigate the shelving of the collective Rydberg excitations to the ground-state manifold, where we observe an order of magnitude increase in the coherence time of the excitation. In the latter half of the thesis, we use near-resonant microwave fields to generate microwave-dressed Rydberg states, where we utilize the degrees of freedom of the microwave field to tune the strength, form, and angular dependence of the dipole-dipole interactions. To this end, we develop a robust and highly tunable microwave polarization control system. We use a set of in-vacuum electrodes as microwave antennas. We measure the microwave polarizations produced by each source at the positions of the atoms using a Rydberg EIT-based polarimetry technique. By characterizing the three imperfect sources, we find the control settings necessary to produce \sigma_-, \pi, and \sigma_+ polarized microwaves with >99 % fidelity. We extend our purification techniques to frequencies away from Rydberg resonances by utilizing an auxiliary microwave field, generating two-photon microwave resonances. The high-fidelity microwave polarizations are used to resonantly admix opposite-parity Rydberg states, generating dressed states with dipole-dipole interactions that are longer range and stronger than the bare van der Waals interactions. To characterize the strength of the interactions, we measure the photon-number statistics of the light generated by the ensemble of atoms. By varying the cloud length relative to the blockade radii, we demonstrate a clear enhancement of the interaction strength due to microwave dressing. Our platform enables further engineering of interactions by exploiting the polarization and frequency degrees of freedom of the microwave fields, opening pathways for new quantum control strategies in many different experimental platforms.

Jan 1, 20250 citations

Mediating gates between polar molecules using microwave-dressed Rydberg atoms

Bas Gerritsen, Sean R. Muleady, Arghavan Safavi-Naini +2 more

We propose a scheme for mediating many simultaneous, fast entangling gates between pairs of polar molecules using Rydberg atoms. By using microwave drives, the dipolar interactions between Rydberg atoms are nullified. Using the freedom left in the microwave dressing parameters, the Rydberg van der Waals interactions are minimized and the Rydberg-molecule interaction is tuned into resonance, allowing for the mediation of a modified iSWAP gate between molecules. In the example of mediating gates between $\rm{{}^{23}Na {}^{133}Cs}$ molecules with $\rm {}^{133}Cs$ atoms, the gate is more than two orders of magnitude faster than an equivalent direct molecule-molecule gate. We model the decay of the dressed Rydberg states and the motion of the atom and molecules and obtain a leading-order estimate of the resulting gate infidelities. Finally, we show that by detecting the state of the Rydberg atom after a gate, a subset of gate errors can be converted into erasure errors and mitigated by post-selection or quantum error-correction.We propose a scheme for mediating many simultaneous, fast entangling gates between pairs of polar molecules using Rydberg atoms. By using microwave drives, the dipolar interactions between Rydberg atoms are nullified. Using the freedom left in the microwave dressing parameters, the Rydberg van der Waals interactions are minimized and the Rydberg-molecule interaction is tuned into resonance, allowing for the mediation of a modified iSWAP gate between molecules. In the example of mediating gates between $\rm{{}^{23}Na {}^{133}Cs}$ molecules with $\rm {}^{133}Cs$ atoms, the gate is more than two orders of magnitude faster than an equivalent direct molecule-molecule gate. We model the decay of the dressed Rydberg states and the motion of the atom and molecules and obtain a leading-order estimate of the resulting gate infidelities. Finally, we show that by detecting the state of the Rydberg atom after a gate, a subset of gate errors can be converted into erasure errors and mitigated by post-selection or quantum error-correction.

quant-pharXiv:2609.28694Sep 25, 20260 citations

Electric Field Tuned Dipolar Interaction Between Rydberg Atoms

Yuechun Jiao, Jingxu Bai, Rong Song +3 more

We demonstrated a tuned dipole interaction between Rydberg atoms by employing a controllable electric field in a cold cesium ensemble. The | n P 3/2 ⟩ ( n = 38–40) Rydberg pairs are prepared with a three-photon scheme and detected via the state-selective field ionization technique. A weak DC electric field is used to tune the Rydberg pair interaction from the van der Waals interaction regime to the dipole–dipole interaction regime. The Förster resonant interaction and an adiabatic resonance energy transfer between the n P and n S Rydberg states are attained by precisely tuning the electric field. Rydberg excitation blockade with and without the electric field is investigated by changing the excitation pulse duration, which demonstrates that the dipole interaction–induced blockade effect is stronger than the van der Waals interaction–induced blockade effect. The precise control of the Rydberg interaction is of great significance to the coherent interaction in many-body systems and non-radiative collision processes.We demonstrated a tuned dipole interaction between Rydberg atoms by employing a controllable electric field in a cold cesium ensemble. The | n P 3/2 ⟩ ( n = 38–40) Rydberg pairs are prepared with a three-photon scheme and detected via the state-selective field ionization technique. A weak DC electric field is used to tune the Rydberg pair interaction from the van der Waals interaction regime to the dipole–dipole interaction regime. The Förster resonant interaction and an adiabatic resonance energy transfer between the n P and n S Rydberg states are attained by precisely tuning the electric field. Rydberg excitation blockade with and without the electric field is investigated by changing the excitation pulse duration, which demonstrates that the dipole interaction–induced blockade effect is stronger than the van der Waals interaction–induced blockade effect. The precise control of the Rydberg interaction is of great significance to the coherent interaction in many-body systems and non-radiative collision processes.

Frontiers in PhysicsApr 27, 20228 citations

Collective Many-Body Interaction in Rydberg Dressed Atoms

Jens Honer, Hendrik Weimer, Tilman Pfau +1 more

We present a method to control the shape and character of the interaction potential between cold atomic gases by weakly dressing the atomic ground state with a Rydberg level. For increasing particle densities, a crossover takes place from a two-particle interaction into a collective many-body interaction, where the dipole-dipole or van der Waals blockade phenomenon between the Rydberg levels plays a dominant role. We study the influence of these collective interaction potentials on a Bose-Einstein condensate and present the optimal parameters for its experimental detection.We present a method to control the shape and character of the interaction potential between cold atomic gases by weakly dressing the atomic ground state with a Rydberg level. For increasing particle densities, a crossover takes place from a two-particle interaction into a collective many-body interaction, where the dipole-dipole or van der Waals blockade phenomenon between the Rydberg levels plays a dominant role. We study the influence of these collective interaction potentials on a Bose-Einstein condensate and present the optimal parameters for its experimental detection.

arXiv:1004.2499Physical Review LettersOct 15, 2010187 citations

\rm{{}^{23}Na {}^{133}Cs}

molecules with

\rm {}^{133}Cs

atoms, the gate is more than two orders of magnitude faster than an equivalent direct molecule-molecule gate. We model the decay of the dressed Rydberg states and the motion of the atom and molecules and obtain a leading-order estimate of the resulting gate infidelities. Finally, we show that by detecting the state of the Rydberg atom after a gate, a subset of gate errors can be converted into erasure errors and mitigated by post-selection or quantum error-correction.