197 research outputs found
Electrophysiological measures of low-level vision reveal spatial processing deficits and hemispheric asymmetry in autism spectrum disorder
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Seconds-scale coherence in a tweezer-array optical clock
Optical clocks based on atoms and ions achieve exceptional precision and
accuracy, with applications to relativistic geodesy, tests of relativity, and
searches for dark matter. Achieving such performance requires balancing
competing desirable features, including a high particle number, isolation of
atoms from collisions, insensitivity to motional effects, and high duty-cycle
operation. Here we demonstrate a new platform based on arrays of ultracold
strontium atoms confined within optical tweezers that realizes a novel
combination of these features by providing a scalable platform for isolated
atoms that can be interrogated multiple times. With this tweezer-array clock,
we achieve greater than 3 second coherence times and record duty cycles up to
96%, as well as stability commensurate with leading platforms. By using optical
tweezer arrays --- a proven platform for the controlled creation of
entanglement through microscopic control --- this work further promises a new
path toward combining entanglement enhanced sensitivities with the most precise
optical clock transitions
A tweezer clock with half-minute atomic coherence at optical frequencies and high relative stability
The preparation of large, low-entropy, highly coherent ensembles of identical
quantum systems is foundational for many studies in quantum metrology,
simulation, and information. Here, we realize these features by leveraging the
favorable properties of tweezer-trapped alkaline-earth atoms while introducing
a new, hybrid approach to tailoring optical potentials that balances
scalability, high-fidelity state preparation, site-resolved readout, and
preservation of atomic coherence. With this approach, we achieve trapping and
optical clock excited-state lifetimes exceeding seconds in ensembles of
approximately atoms. This leads to half-minute-scale atomic coherence
on an optical clock transition, corresponding to quality factors well in excess
of . These coherence times and atom numbers reduce the effect of
quantum projection noise to a level that is on par with leading atomic systems,
yielding a relative fractional frequency stability of
for synchronous clock comparisons
between sub-ensembles within the tweezer array. When further combined with the
microscopic control and readout available in this system, these results pave
the way towards long-lived engineered entanglement on an optical clock
transition in tailored atom arrays.Comment: 11 pages, 5 figures (main text); 17 pages, 7 figures (supplemental
materials
Mid-circuit qubit measurement and rearrangement in a Yb atomic array
Measurement-based quantum error correction relies on the ability to determine
the state of a subset of qubits (ancillae) within a processor without revealing
or disturbing the state of the remaining qubits. Among neutral-atom based
platforms, a scalable, high-fidelity approach to mid-circuit measurement that
retains the ancilla qubits in a state suitable for future operations has not
yet been demonstrated. In this work, we perform imaging using a
narrow-linewidth transition in an array of tweezer-confined Yb atoms to
demonstrate nondestructive state-selective and site-selective detection. By
applying site-specific light shifts, selected atoms within the array can be
hidden from imaging light, which allows a subset of qubits to be measured while
causing only percent-level errors on the remaining qubits. As a
proof-of-principle demonstration of conditional operations based on the results
of the mid-circuit measurements, and of our ability to reuse ancilla qubits, we
perform conditional refilling of ancilla sites to correct for occasional atom
loss, while maintaining the coherence of data qubits. Looking towards true
continuous operation, we demonstrate loading of a magneto-optical trap with a
minimal degree of qubit decoherence.Comment: 9 pages, 6 figure
Seamless tuning range based-on available gain bandwidth in multiwavelength Brillouin fiber laser.
We experimentally demonstrate a simple widely tunable multiwavelength Brillouin/Erbium fiber laser that can be tuned over the entire C-band, thereby greatly improving the tuning range limitation faced by the previous Brillouin-erbium fiber laser architectures. Tuning range of 39 nm from 1527 nm to 1566 nm, which is only limited by the amplification bandwidth of the erbium gain was successfully achieved. At Brillouin pump wavelength of 1550 nm and 1480 nm laser pump and Brillouin pump powers of 130 mW and 2 mW respectively, all the generated output channels have peak power above 0 dBm, with the first output channel having a peak power of 8.52 dBm. The experimental set up that consists of only 4 optical components, is simple, devoid of the complex structure employed previously to enhance the tunability and feedback mechanism normally associated with multiwavelength Brillouin-erbium fiber laser sources. The generated output channels are stable, rigidly separated by 10 GHz (0.08 nm)
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