Lifeboat Foundation

When a positive voltage was applied to the chip, the ions flowed to the pore, where their pressure created a blister between the chip’s surface and the graphite layer. When the blister forced the graphite upward, the device became more conductive, switching its memory state to “on.” Since the graphite stayed lifted even without a current, the chip essentially remembered this state, A negative voltage could pull the chip’s layers back together, resetting the device to its “off” state.

The scientists were able to connect two of these chips to form a logic gate —a circuit that can implement logical operations such as AND, OR, and NOT. They note they can build any other classical logic gate commonly employed in digital computing using their logic gate. This is the first time multiple fluidic memristors have been connected to form a circuit.

Previously, scientists developed fluidic memristors based on tiny syringes or microscopic slits. However, these earlier devices were too bulky and complex to scale up to larger systems. In contrast, the new microchips are compact and scalable, Emmerich says.

Birds flock. Locusts swarm. Fish school. Within assemblies of organisms that seem as though they could get chaotic, order somehow emerges. The collective behaviors of animals differ in their details from one species to another, but they largely adhere to principles of collective motion that physicists have worked out over centuries. Now, using technologies that only recently became available, researchers have been able to study these patterns of behavior more closely than ever before.

In this episode, the evolutionary ecologist Iain Couzin talks with co-host Steven Strogatz about how and why animals exhibit collective behaviors, flocking as a form of biological computation, and some of the hidden fitness advantages of living as part of a self-organized group rather than as an individual. They also discuss how an improved understanding of swarming pests such as locusts could help to protect global food security.

Listen on Apple Podcasts, Spotify, Google Podcasts, TuneIn or your favorite podcasting app, or you can stream it from Quanta.

Programming the Universe: A Quantum Computer Scientist Takes on the Cosmos. Seth Lloyd. xii + 221 pp. Alfred A. Knopf, 2006. $25.95.

In the 1940s, computer pioneer Konrad Zuse began to speculate that the universe might be nothing but a giant computer continually executing formal rules to compute its own evolution. He published the first paper on this radical idea in 1967, and since then it has provoked an ever-increasing response from popular culture (the film The Matrix, for example, owes a great deal to Zuse’s theories) and hard science alike.

Ever wonder where all the active supermassive black holes are in the universe? Now, with the largest quasar catalog yet, you can see the locations of 1.3 million quasars in 3D.

The catalog, Quaia, can be accessed here.

“This quasar catalog is a great example of how productive astronomical projects are,” says David Hogg, study co-author and computational astrophysicist at the Flatiron Institute, in a press release. “Gaia was designed to measure stars in our galaxy, but it also found millions of quasars at the same time, which give us a map of the entire universe.” By mapping and seeing where quasars are across the universe, astrophysicists can learn more about how the universe evolved, insights into how supermassive black holes grow, and even how dark matter clumps together around galaxies. Researchers published the study this week in The Astrophysical Journal.

Quantum cognition is a new research program that uses mathematical principles from quantum theory as a framework to explain human cognition, including judgment and decision making, concepts, reasoning, memory, and perception. This research is not concerned with whether the brain is a quantum computer. Instead, it uses quantum theory as a fresh conceptual framework and a coherent set of formal tools for explaining puzzling empirical findings in psychology. In this introduction, we focus on two quantum principles as examples to show why quantum cognition is an appealing new theoretical direction for psychology: complementarity, which suggests that some psychological measures have to be made sequentially and that the context generated by the first measure can influence responses to the next one, producing measurement order effects, and superposition, which suggests that some psychological states cannot be defined with respect to definite values but, instead, that all possible values within the superposition have some potential for being expressed. We present evidence showing how these two principles work together to provide a coherent explanation for many divergent and puzzling phenomena in psychology. (PsycInfo Database Record © 2020 APA, all rights reserved)

An article in Nature Electronics presents how to use electron-beam lithography to obtain p-and n-type vertical organic electrochemical transistor matrix arrays and complementary logic circuits.

Advances with photoswitches could lead to a smartphone that’s soft and flexible and shaped like a hand so you can wear it as a glove, for example. Or a paper-thin computer screen that you can roll up like a window shade when you’re done using it. Or a TV as thin as wallpaper that you can paste on a wall and hardly know it’s there when you’re not watching it.

Photoswitches, which turn on and off in response to light, can be stitched together to replace the transistors used in electronic devices that control the flow of the electric current.

Commercial silicon transistors are brittle, nontransparent, and typically several microns thick, about the same thickness as a red blood cell. In contrast, photoswitches are one or two nanometers, about 1,000 times thinner. They can also be mounted on graphene, a transparent, flexible material.

Researchers have developed a carbon nanotube (CNT) transistor for molecule glasses that facilitates detailed examination of molecular interactions. This innovative technology is poised to open a fresh research direction in nanotechnology and molecular biology.

Nanoscale transistors are in demand for efficient digital circuits, and biasing of each device is critical. These stringent biasing conditions can be relaxed by obtaining precise values of the threshold voltages of the transistor. This leads to more tolerant logic states to the electrical noise.

To meet the requirements of reduced power consumption, CMOS field-effect transistors (FETs) are fabricated such that they operate in enhancement (E) mode, i.e., there are no free charge carriers in the channel at zero gate voltage. On the other hand, depletion (D) mode transistors have higher currents than enhancement mode due to ample charge carrier density.

In contrast to switching applications of FET, for high-frequency applications, off-state of FET is not a compulsory requirement. In fact, the presence of a channel at zero gate bias is advantageous to obtain high transconductance at lower voltages. For Si FETs, the enhancement or depletion modes were determined at the fabrication step of ion implantation doping. However, it is challenging to implement this solution for the new generation of thin materials like organic semiconductors and 2D materials.