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Jau, Yuan-Yu

Publications and source records attributed to Jau, Yuan-Yu.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Detection and imaging of electric fields, using polarized neutrons

A method and corresponding apparatus are provided for measuring neutron spin precession in an electric field with high sensitivity suitable for practical applications in non-destructive testing, imaging, and the like. Production of a neutron beam with a polarization vector P is followed by transmitting the spin-polarized neutron beam through a sample region in which there is a target generating an electric field, polarization-analyzing the transmitted neutron beam with an analyzing direction orthogonal to P, detecting an intensity of the polarization-analyzed neutron beam; and mapping the detected neutron-beam intensity to a field-strength value for the target electric field.

Jau, Yuan-Yu↗
DOE OSTI2024

Guided cold atom inertial sensors with membrane integrated photonics on atom trap integrated platforms

A guided cold-atom inertial sensor system comprises an atom trap integrated platform, a laser system, a magnetic field system, a control system, and a computing system. The laser system and magnetic field system are adapted to form a magneto-optical trap (MOT) about a suspended waveguide of the atom trap integrated platform made of membrane integrated photonics. After loading cold atoms from a MOT, the photonic atom trap integrated platform generates one-dimensional guided atoms with an evanescent field optical dipole trap (EF-ODT) along the optical waveguide to create guided atomic accelerometers/gyroscopes. Motion of atomic wavepackets in a superposition state is created along the guided atom geometry by way of state-dependent momentum kicks. The light-pulse sequence of guided atom interferometry splits, redirects, and recombines atomic wavepackets, which allows measurement of atom interference fringes sensitive to inertial forces via a probe laser.

Lee, Jongmin↗
DOE OSTI2024

Suspended waveguides on membrane and needle structures towards photonic atom trap integrated platforms

An atom trap integrated platform (ATIP) comprises a substrate, a membrane, and a suspended waveguide. The substrate has an opening formed therein. The membrane extends across a portion of the substrate opening. The suspended waveguide is formed on the membrane such that the suspended waveguide extends from a first edge of the substrate to a second edge. A magneto-optical trap (MOT) is formed around the suspended waveguide by emitting a plurality of cooling beams and a repump through the substrate opening. Evanescent fields are established above the suspended waveguide by coupling two trapping beams through the suspended waveguide, which trapping beams are red-detuned and blue-detuned with respect to the resonant optical transition of the atoms. By forming the MOT within the evanescent fields, an evanescent field optical trap (EFOT) is formed.

Lee, Jongmin↗
DOE OSTI2024

Entangling quantum logic gates in neutral atoms via the microwave-driven spin-flip blockade

The Rydberg dipole blockade has emerged as the standard mechanism to induce entanglement between neutral-atom qubits. In these protocols, laser fields that couple qubit states to Rydberg states are modulated to implement entangling gates. Here, in this study, we present an alternative protocol to implement entangling gates via Rydberg dressing and a microwave-field-driven spin-flip blockade. We consider the specific example of qubits encoded in the clock states of cesium. An auxiliary hyperfine state is optically dressed so that it acquires partial Rydberg character. It thus acts as a proxy Rydberg state, with a nonlinear light shift that plays the role of blockade strength. A microwave-frequency field coupling a qubit state to this dressed auxiliary state can be modulated to implement entangling gates. Logic gate protocols designed for the optical regime can be imported to this microwave regime, for which experimental control methods are more robust. We show that unlike the strong dipole-blockade regime usually employed in Rydberg experiments, going to a moderate-spin-flip-blockade regime results in faster gates and smaller Rydberg decay. We study various regimes of operations that can yield high-fidelity two-qubit entangling gates and characterize their analytical behavior. In addition to the inherent robustness of microwave control, we can design these gates to be more robust to laser amplitude and frequency noises at the cost of a small increase in Rydberg decay.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2023

Low-frequency atomic electrometry

In a method of atomic electrometry, EIT spectroscopy is performed on host atoms of an alkali metal in a vapor cell. The EIT spectroscopy indicates a resonant energy of a probed Rydberg state of the host atoms. The vapor cell is exposed to an ambient electric field. A shift in the resonant energy as indicated by the EIT spectroscopy is observed and interpreted as a measurement of the ambient field. During the measurement of the ambient field, a bias electric field is generated inside the vapor cell by shining light into the vapor cell from a light source situated outside of the cell. The bias field is useful for increasing the sensitivity of the measurement.

Jau, Yuan-Yu↗
DOE OSTI2023

Optically pumped gradient magnetometer

A method is provided for sensing a magnetic field in a magnetic gradiometer of the kind in which pump light and light constituting an optical carrier traverse first and second atomic vapor cells that contain host atoms and that are separated from each other by a known distance. According to such method, the host atoms are prepared in a coherent superposition of two quantum states that differ in energy by an amount that is sensitive to an ambient magnetic field. Modulation of the optical carrier in the respective cells gives rise to sidebands that interfere to generate a beat frequency indicative of the magnetic field gradient. The host atoms are prepared at least in a mode that allows measurement of ambient magnetic field components perpendicular to the axis of the pump light. In such mode, the host atoms are spin-polarized by pump light while subjected to a controlled magnetic field directed parallel to the pump beam, and then the controlled magnetic field is adiabatically extinguished.

47 OTHER INSTRUMENTATION↗