15 research outputs found
Realizing two-qubit gates through mode engineering on a trapped-ion quantum computer
Two-qubit gates are a fundamental constituent of a quantum computer and
typically its most challenging operation. In a trapped-ion quantum computer,
this is typically implemented with laser beams which are modulated in
amplitude, frequency, phase, or a combination of these. The required modulation
becomes increasingly more complex as the quantum computer becomes larger,
complicating the control hardware design. Here, we develop a simple method to
essentially remove the pulse-modulation complexity by engineering the normal
modes of the ion chain. We experimentally demonstrate the required mode
engineering in a three ion chain. This opens up the possibility to trade off
complexity between the design of the trapping fields and the optical control
system, which will help scale the ion trap quantum computing platform.Comment: arXiv admin note: text overlap with arXiv:2104.13870 Updated funding
informatio
Para-particle oscillator simulations on a trapped ion quantum computer
Deformed oscillators allow for a generalization of the standard fermions and
bosons, namely, for the description of para-particles. Such particles, while
indiscernible in nature, can represent good candidates for descriptions of
physical phenomena like topological phases of matter. Here, we report the
digital quantum simulation of para-particle oscillators by mapping
para-particle states to the state of a qubit register, which allow us to
identify the para-particle oscillator Hamiltonian as an model, and further
digitize the system onto a universal set of gates. In both instances, the gate
depth grows polynomially with the number of qubits used. To establish the
validity of our results, we experimentally simulate the dynamics of
para-fermions and para-bosons, demonstrating full control of para-particle
oscillators on a quantum computer. Furthermore, we compare the overall
performance of the digital simulation of dynamics of the driven para-Fermi
oscillator to a recent analog quantum simulation result.Comment: 7 pages, 5 figures, 1 tabl
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Multi-round QAOA and advanced mixers on a trapped-ion quantum computer
Combinatorial optimization problems on graphs have broad applications in
science and engineering. The Quantum Approximate Optimization Algorithm (QAOA)
is a method to solve these problems on a quantum computer by applying multiple
rounds of variational circuits. However, there exist several challenges
limiting the real-world applications of QAOA. In this paper, we demonstrate on
a trapped-ion quantum computer that QAOA results improve with the number of
rounds for multiple problems on several arbitrary graphs. We also demonstrate
an advanced mixing Hamiltonian that allows sampling of all optimal solutions
with predetermined weights. Our results are a step towards applying quantum
algorithms to real-world problems.Comment: 8 pages, 5 figure
The eleventh and twelfth data releases of the Sloan Digital Sky Survey : final data from SDSS-III
The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new nearinfrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra