3 research outputs found
Inductively guided circuits for ultracold dressed atoms
Recent progress in optics, atomic physics and material science has paved the way to study quantum effects in ultracold atomic alkali gases confined to non-trivial geometries. Multiply connected traps for cold atoms can be prepared by combining inhomogeneous distributions of DC and radio-frequency electromagnetic fields with optical fields that require complex systems for frequency control and stabilization. Here we propose a flexible and robust scheme that creates closed quasi-one-dimensional guides for ultracold atoms through the ‘dressing’ of hyperfine sublevels of the atomic ground state, where the dressing field is spatially modulated by inductive effects over a micro-engineered conducting loop. Remarkably, for commonly used atomic species (for example, 7Li and 87Rb), the guide operation relies entirely on controlling static and low-frequency fields in the regimes of radio-frequency and microwave frequencies. This novel trapping scheme can be implemented with current technology for micro-fabrication and electronic control
Field-sensitive addressing and control of field-insensitive neutral-atom qubits
The establishment of a scalable scheme for quantum computing with addressable
and long-lived qubits would be a scientific watershed, harnessing the laws of
quantum physics to solve classically intractable problems. The design of many
proposed quantum computational platforms is driven by competing needs:
isolating the quantum system from the environment to prevent decoherence, and
easily and accurately controlling the system with external fields. For example,
neutral-atom optical-lattice architectures provide environmental isolation
through the use of states that are robust against fluctuating external fields,
yet external fields are essential for qubit addressing. Here we demonstrate the
selection of individual qubits with external fields, despite the fact that the
qubits are in field-insensitive superpositions. We use a spatially
inhomogeneous external field to map selected qubits to a different
field-insensitive superposition ("optical MRI"), minimally perturbing
unselected qubits, despite the fact that the addressing field is not spatially
localized. We show robust single-qubit rotations on neutral-atom qubits located
at selected lattice sites. This precise coherent control is an important step
forward for lattice-based neutral-atom quantum computation, and is quite
generally applicable to state transfer and qubit isolation in other
architectures using field-insensitive qubits.Comment: press embarg