Quantum optical waveform conversion

Currently proposed architectures for long-distance quantum communication rely on networks of quantum processors connected by optical communications channels [1,2]. The key resource for such networks is the entanglement of matter-based quantum systems with quantum optical fields for information transmission. The optical interaction bandwidth of these material systems is a tiny fraction of that available for optical communication, and the temporal shape of the quantum optical output pulse is often poorly suited for long-distance transmission. Here we demonstrate that nonlinear mixing of a quantum light pulse with a spectrally tailored classical field can compress the quantum pulse by more than a factor of 100 and flexibly reshape its temporal waveform, while preserving all quantum properties, including entanglement. Waveform conversion can be used with heralded arrays of quantum light emitters to enable quantum communication at the full data rate of optical telecommunications.Comment: submitte

Radio frequency emissions from dark-matter-candidate magnetized quark nuggets interacting with matter

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks. They are also called strangelets, nuclearites, AQNs, slets, Macros, and MQNs. Quark nuggets are a candidate for dark matter, which has been a mystery for decades despite constituting ~ 85% of the universe’s mass. Most previous models of quark nuggets have assumed no intrinsic magnetic field; however, Tatsumi found that quark nuggets may exist in magnetars as a ferromagnetic liquid with a magnetic field BS = 1012±1 T. We apply that result to quark nuggets, a dark-matter candidate consistent with the Standard Model, and report results of analytic calculations and simulations that show they spin up and emit electromagnetic radiation at ~ 104 to ~ 109 Hz after passage through planetary environments. The results depend strongly on the value of Bo, which is a parameter to guide and interpret observations. A proposed sensor system with three satellites at 51,000 km altitude illustrates the feasibility of using radio-frequency emissions to detect 0.003 to 1,600 MQNs, depending on Bo, during a 5 year mission

Detection of magnetized quark-nuggets, a candidate for dark matter

AbstractQuark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks and are also called strangelets and nuclearites. They have been proposed as a candidate for dark matter, which constitutes ~85% of the universe’s mass and which has been a mystery for decades. Previous efforts to detect quark nuggets assumed that the nuclear-density core interacts directly with the surrounding matter so the stopping power is minimal. Tatsumi found that quark nuggets could well exist as a ferromagnetic liquid with a ~1012-T magnetic field. We find that the magnetic field produces a magnetopause with surrounding plasma, as the earth’s magnetic field produces a magnetopause with the solar wind, and substantially increases their energy deposition rate in matter. We use the magnetopause model to compute the energy deposition as a function of quark-nugget mass and to analyze testing the quark-nugget hypothesis for dark matter by observations in air, water, and land. We conclude the water option is most promising.</jats:p

Decoherence due to elastic Rayleigh scattering

We present theoretical and experimental studies of the decoherence of hyperfine ground-state superpositions due to elastic Rayleigh scattering of light off-resonant with higher lying excited states. We demonstrate that under appropriate conditions, elastic Rayleigh scattering can be the dominant source of decoherence, contrary to previous discussions in the literature. We show that the elastic-scattering decoherence rate of a two-level system is given by the square of the difference between the elastic-scattering \textit{amplitudes} for the two levels, and that for certain detunings of the light, the amplitudes can interfere constructively even when the elastic scattering \textit{rates} from the two levels are equal. We confirm this prediction through calculations and measurements of the total decoherence rate for a superposition of the valence electron spin levels in the ground state of $^9$Be$^+$ in a 4.5 T magnetic field.Comment: 5 pages, 3 figure

Results of search for magnetized quark-nugget dark matter from radial impacts on Earth

Magnetized Quark Nuggets (MQNs) are a recently proposed dark-matter candidate consistent with the Standard Model and with Tatsumi's theory of quark-nugget cores in magnetars. Previous publications have covered their formation in the early universe, aggregation into a broad mass distribution before they can decay by the weak force, interaction with normal matter through their magnetopause, and first observation consistent MQNs, i.e. a nearly tangential impact limiting their surface-magnetic-field parameter B_o from Tatsumi's values of 0.1 to 10.0 TT to new value of 1.65 TT +/- 21%. The MQN mass distribution and interaction cross section depend strongly on B_o. Their magnetopause is much larger than their geometric dimensions and can cause sufficient energy deposition to form non-meteorite craters, which are reported approximately annually. We report computer simulations of the MQN energy deposition in water-saturated peat, soft sediments, and granite and report results from excavating such a crater. Five points of agreement between observations and hydrodynamic simulations of an MQN impact support this second observation consistent with MQN dark matter and suggest a method for qualifying additional MQN events. The results also redundantly constrain B_o to greater than 0.4 TT.Comment: 30 pages, 13 figures, submitted to Univers

High fidelity transport of trapped-ion qubits through an X-junction trap array

We report reliable transport of 9Be+ ions through a 2-D trap array that includes a separate loading/reservoir zone and an "X-junction". During transport the ion's kinetic energy in its local well increases by only a few motional quanta and internal-state coherences are preserved. We also examine two sources of energy gain during transport: a particular radio-frequency (RF) noise heating mechanism and digital sampling noise. Such studies are important to achieve scaling in a trapped-ion quantum information processor.Comment: 4 pages, 3 figures Updated to reduce manuscript to four pages. Some non-essential information was removed, including some waveform information and more detailed information on the tra