Catálogo de publicaciones - revistas

<jats:title>Toward the control of light with light</jats:title> <jats:p> Optic fibers form the backbone of the communications sector and carry huge amounts of data around the globe. Nissim <jats:italic>et al.</jats:italic> show that small perturbations within the core of a fiber give rise to interactions between photons. The strength of the interaction could be controlled by carefully characterizing and splicing together different lengths of fiber. The interactions between the photons were enhanced so that a strong signal beam could be switched off with just a few photons. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="417" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253125">417</jats:related-article> </jats:p>

<jats:title>How to benchmark a quantum computer</jats:title> <jats:p> Quantum machines offer the possibility of performing certain computations much faster than their classical counterparts. However, how to define and measure quantum speedup is a topic of debate. Rønnow <jats:italic>et al.</jats:italic> describe methods for fairly evaluating the difference in computational power between classical and quantum processors. They define various types of quantum speedup and consider quantum processors that are designed to solve a specific class of problems. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="420" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1252319">420</jats:related-article> </jats:p>

<jats:title>Subtle entanglement in an atomic cloud</jats:title> <jats:p> In the quantum world, atoms can be correlated with each other—“entangled”—which reduces the uncertainty in the knowledge of some of their properties. Physicists then use this reduced uncertainty to perform precision measurements. Strobel <jats:italic>et al.</jats:italic> made an unusual type of entangled state consisting of hundreds of ultracold Rb atoms. These methods may in the future be able to generate states that will be more useful in precision measurement. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="424" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1250147">424</jats:related-article> </jats:p>

<jats:title>To cast no shadow in a murky medium</jats:title> <jats:p> Cloaks can hide objects from view, but what about their shadows? Schittny <jats:italic>et al.</jats:italic> devised a cloak to remove even the shadow of an object embedded in a murky medium in front of a computer screen (see the Perspective by Smith). They engineered a core-shell structure within which an object could be hidden and tailored the optical properties of the cloak to match that of the medium. Light was routed around the cloak, leaving no trace of the hidden object. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="427" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254524">427</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="384" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1256753">384</jats:related-article> </jats:p>

<jats:title>Characterization of a quantum simulator</jats:title> <jats:p> Ultracold gases can be used to simulate the behavior of more complicated systems, such as solid materials. Senko <jats:italic>et al.</jats:italic> developed a method similar to nuclear magnetic resonance that can be used to validate the properties of such simulators. They demonstrated the method on an array of interacting trapped ions that simulate magnetism. A modulated magnetic field resonantly enhanced the transfer of the population between the different configurations of the system. The authors varied the modulation frequency to measure the energy of each configuration and mapped the effective interactions. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="430" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1251422">430</jats:related-article> </jats:p>

<jats:title>A bright outlook for carbon coupling</jats:title> <jats:p> In contemporary organic chemistry, it is straightforward to forge bonds between unsaturated carbons (i.e., carbons already engaged in double bonds) using cross-coupling catalysis. The protocol runs into some trouble, however, if one or both starting carbon centers are saturated (purely single-bonded). Tellis <jats:italic>et al.</jats:italic> and Zuo <jats:italic>et al.</jats:italic> independently found that combining a second, light-activated catalyst with a nickel cross-coupling catalyst could achieve selective coupling of saturated and unsaturated reagents (see the Perspective by Lloyd-Jones and Ball). Their methods rely on single-electron transfer from the light-activated catalyst to the saturated carbon, thereby enhancing its reactivity more effectively than the twoelectron mechanisms prevailing in traditional protocols. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="433" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253647">433</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="437" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1255525">437</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="381" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1256755">381</jats:related-article> </jats:p>

<jats:title>A bright outlook for carbon coupling</jats:title> <jats:p> In contemporary organic chemistry, it is straightforward to forge bonds between unsaturated carbons (i.e., carbons already engaged in double bonds) using cross-coupling catalysis. The protocol runs into some trouble, however, if one or both starting carbon centers are saturated (purely single-bonded). Tellis <jats:italic>et al.</jats:italic> and Zuo <jats:italic>et al.</jats:italic> independently found that combining a second, light-activated catalyst with a nickel cross-coupling catalyst could achieve selective coupling of saturated and unsaturated reagents (see the Perspective by Lloyd-Jones and Ball). Their methods rely on single-electron transfer from the light-activated catalyst to the saturated carbon, thereby enhancing its reactivity more effectively than the twoelectron mechanisms prevailing in traditional protocols. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="433" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253647">433</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="437" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1255525">437</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6195" page="381" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1256755">381</jats:related-article> </jats:p>