11 research outputs found
Toward Quantum Analog Computing: Simulating Designer Atomic Systems
We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer and look for opportunities to control the energy exchange by manipulating the geometry. We present results that could be applicable for quantum information processing
Toward Analog Quantum Computing: Simulating Designer Atomic Systems
We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer and look for opportunities to control the energy exchange by manipulating the geometry. We present results that could be applicable for quantum information processing
Simulations of the angular dependence of the dipole-dipole interaction among Rydberg atoms
The dipole-dipole interaction between two Rydberg atoms depends on the
relative orientation of the atoms and on the change in the magnetic quantum
number. We simulate the effect of this anisotropy on the energy transport in an
amorphous many atom system subject to a homogeneous applied electric field. We
consider two experimentally feasible geometries and find that the effects
should be measurable in current generation imaging experiments. In both
geometries atoms of character are localized to a small region of space
which is immersed in a larger region that is filled with atoms of
character. Energy transfer due to the dipole-dipole interaction can lead to a
spread of character into the region initially occupied by atoms. Over
long timescales the energy transport is confined to the volume near the border
of the region which is suggestive of Anderson localization. We calculate a
correlation length of 6.3~m for one particular geometry.Comment: 6 pages, 5 figures, revised draf
Skunk River Review September 1992, Vol 4
https://openspace.dmacc.edu/skunkriver/1007/thumbnail.jp
In situ detection of boron by ChemCam on Mars
We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater
The Wall Street Walk when Blockholders Compete for Flows
An important recent theoretical literature argues that the threat of exit can represent an effective form of governance when the blockholder is a principal. However, a significant fraction of equity blocks is held by delegated portfolio managers. How do agency frictions arising from the delegation of portfolio management affect the ability of blockholders to govern via the threat of exit? We show that when blockholders are sufficiently career concerned exit will fail as a disciplining device. Our results have testable implications on the relative degree to which different classes of delegated portfolio managers use exit as a form of governance