Abstract
Decoherence of quantum systems due to uncontrolled fluctuations of the environment presents fundamental obstacles in quantum science. Clock transitions which are insensitive to such fluctuations are used to improve coherence, however, they are not present in all systems or for arbitrary system parameters. Here we create a trio of synthetic clock transitions using continuous dynamical decoupling in a spin-1 Bose-Einstein condensate in which we observe a reduction of sensitivity to magnetic-field noise of up to four orders of magnitude; this work complements the parallel work by Anderson et al.. In addition, using a concatenated scheme, we demonstrate suppression of sensitivity to fluctuations in our control fields. These field-insensitive states represent an ideal foundation for the next generation of cold-atom experiments focused on fragile many-body phases relevant to quantum magnetism, artificial gauge fields, and topological matter.
Highlights
The loss of coherence due to uncontrolled coupling to a fluctuating environment is a limiting performance factor for quantum technologies [1,2,3,4]
The Continuous dynamical decoupling (CDD)-protected states are sensitive to fluctuations of the amplitude of the control field, and we demonstrate that a second coupling field protects against those in a concatenated manner [6,10,16]
We realized a three-level system that is dynamically decoupled from low-frequency noise, measured now-allowed transitions between all three states, and demonstrated control techniques for creating arbitrary Hamiltonians. These techniques add no heating or loss mechanisms, yet within the protected subspace retain the full complement of cold-atom coherent control tools such as optical lattices and Raman laser coupling and permit new first-order transitions that are absent in the unprotected subspace. These transitions enable experiments requiring a fully connected geometry as for engineering exotic states, e.g., in cold-atom topological insulators, and two-dimensional Rashba spin-orbit coupling in ultracold atomic systems [25,26]
Summary
The loss of coherence due to uncontrolled coupling to a fluctuating environment is a limiting performance factor for quantum technologies [1,2,3,4]. Under almost all circumstances, clock transitions can be synthesized using dynamical decoupling protocols. These protocols involve driving the system with an external oscillatory field, resulting in a dynamically protected dressed system. A number of dynamical decoupling protocols, pulsed or continuous, have been shown to isolate quantum systems from low-frequency environmental noise [6,7,8,9,10,11,12,13,14]. We demonstrate CDD in atomic Bose-Einstein condensates (BECs) producing a protected three-level system of dressed states, whose Hamiltonian is fully controllable.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
