Arrays of individually controlled ions suitable for two-dimensional quantum simulations

A precisely controlled quantum system may reveal a fundamental understanding of another, less accessible system of interest. A universal quantum computer is currently out of reach, but an analogue quantum simulator that makes relevant observables, interactions and states of a quantum model accessible could permit insight into complex dynamics. Several platforms have been suggested and proof-of-principle experiments have been conducted. Here, we operate two-dimensional arrays of three trapped ions in individually controlled harmonic wells forming equilateral triangles with side lengths 40 and 80 μm. In our approach, which is scalable to arbitrary two-dimensional lattices, we demonstrate individual control of the electronic and motional degrees of freedom, preparation of a fiducial initial state with ion motion close to the ground state, as well as a tuning of couplings between ions within experimental sequences. Our work paves the way towards a quantum simulator of two-dimensional systems designed at will

Finds from the fill of well A.

<p>(<i>A</i>) Well A during excavation. Within the square wooden lining, a dense deposition of pottery consisting of intact and broken vessels has been uncovered. (<i>B</i>) Selection of intact and restored pots representative of the ceramic spectrum of the LBK, consisting of jars, necked vessels and bowls (to scale, photorealistic renderings of laser scans). (<i>C</i>) Complete ear of Einkorn (<i>Triticum monococcum</i>, 70 mm in length) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051374#pone.0051374-Becker1" target="_blank">[27]</a>.</p

Early Neolithic Water Wells Reveal the World's Oldest Wood Architecture

<div><p>The European Neolithization ∼6000−4000 BC represents a pivotal change in human history when farming spread and the mobile style of life of the hunter-foragers was superseded by the agrarian culture. Permanent settlement structures and agricultural production systems required fundamental innovations in technology, subsistence, and resource utilization. Motivation, course, and timing of this transformation, however, remain debatable. Here we present annually resolved and absolutely dated dendroarchaeological information from four wooden water wells of the early Neolithic period that were excavated in Eastern Germany. A total of 151 oak timbers preserved in a waterlogged environment were dated between 5469 and 5098 BC and reveal unexpectedly refined carpentry skills. The recently discovered water wells enable for the first time a detailed insight into the earliest wood architecture and display the technological capabilities of humans ∼7000 years ago. The timbered well constructions made of old oak trees feature an unopened tree-ring archive from which annually resolved and absolutely dated environmental data can be culled. Our results question the principle of continuous evolutionary development in prehistoric technology, and contradict the common belief that metal was necessary for complex timber constructions. Early Neolithic craftsmanship now suggests that the first farmers were also the first carpenters.</p> </div

Early Neolithic craftsmanship from well A. 3D laser rendering of (<i>A</i>) a timber bearing tool marks on the surface, (<i>B</i>) various timbers with cogging joints.

<p>(<i>C</i>) 3D model of the well lining set-up using laser images. (<i>D</i>) Sketch of the base frame with wedged tusk tenon joints and the frame with interlocked corner joints.</p

Wooden well constructions and Neolithization.

<p>LBK wells from (<i>A</i>) Eythra 1, (<i>B</i>) Eythra 2, (<i>C</i>) Brodau 1, and (<i>D</i>) Altscherbitz. (<i>E</i>) Central European loess distribution <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051374#pone.0051374-Haase1" target="_blank">[20]</a> with the superimposed phases of expansion of the LBK (lines), based on ¹⁴C dates <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051374#pone.0051374-Stuble2" target="_blank">[22]</a>, and the maximum extension of the LBK (light blue) along with the 12 known early Neolithic wells featuring waterlogged wood preservation.</p

Basal frame construction of well A.

<p>(<i>A</i>) Wedged tusk tenon joint. (<i>B</i>) 3D laser rendering of the basal frame.</p