InSight sensors captured a haunting low rumble caused by vibrations from the wind, estimated to be blowing between 10 to 15 mph (5 to 7 meters a second) on Dec. 1, from northwest to southeast. The winds were consistent with the direction of dust devil streaks in the landing area, which were observed from orbit.

“Capturing this audio was an unplanned treat,” said Bruce Banerdt, InSight principal investigator at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “But one of the things our mission is dedicated to is measuring motion on Mars, and naturally that includes motion caused by sound waves.”

Teleconference audio and accompanying visuals will stream live on NASA’s website (www.nasa.gov/live). A follow-along page is available at:

https://www.nasa.gov/insightmarswind

Two very sensitive sensors on the spacecraft detected these wind vibrations: an air pressure sensor inside the lander and a seismometer sitting on the lander’s deck, awaiting deployment by InSight’s robotic arm. The two instruments recorded the wind noise in different ways. The air pressure sensor, part of the Auxiliary Payload Sensor Subsystem (APSS), which will collect meteorological data, recorded these air vibrations directly. The seismometer recorded lander vibrations caused by the wind moving over the spacecraft’s solar panels, which are each 7 feet (2.2 meters) in diameter and stick out from the sides of the lander like a giant pair of ears.

This is the only phase of the mission during which the seismometer, called the Seismic Experiment for Interior Structure SEIS, will be capable of detecting vibrations generated directly by the lander. In a few weeks, it will be placed on the Martian surface by InSight’s robotic arm, then covered by a domed shield to protect it from wind and temperature changes. It still will detect the lander’s movement, though channeled through the Martian surface. For now, it’s recording vibrational data that scientists later will be able to use to cancel out noise from the lander when SEIS is on the surface, allowing them to detect better actual marsquakes.

When earthquakes occur on Earth, their vibrations, which bounce around inside our planet, make it “ring” similar to how a bell creates sound. InSight will see if tremors, or marsquakes, have a similar effect on Mars. SEIS will detect these vibrations that will tell us about the Red Planet’s deep interior. Scientists hope this will lead to new information on the formation of the planets in our solar system, perhaps even of our own planet.

SEIS, France’s Centre National d’Études Spatiales (CNES), includes two sets of seismometers. Those contributed by the French will be used once SEIS is deployed from the deck of the lander. But SEIS also includes short period (SP) silicon sensors developed by Imperial College London with electronics from Oxford University in the United Kingdom. These sensors can work while on the deck of the lander and are capable of detecting vibrations up to frequencies of nearly 50 hertz, at the lower range of human hearing.

“The InSight lander acts like a giant ear,” said Tom Pike, InSight science team member and sensor designer at Imperial College London. “The solar panels on the lander’s sides respond to pressure fluctuations of the wind. It’s like InSight is cupping its ears and hearing the Mars wind beating on it. When we looked at the direction of the lander vibrations coming from the solar panels, it matches the expected wind direction at our landing site.”

Pike compared the effect to a flag in the wind. As a flag breaks up the wind, it creates oscillations in air pressure that the human ear perceives as flapping. Separately, APSS records changes in pressure directly from the thin Martian air.

“That’s literally what sound is — changes in air pressure,” said Don Banfield InSight’s science lead for APSS from Cornell University in Ithaca, New York. “You hear that whenever you speak to someone across the room.”

Unlike the vibrations recorded by the short period sensors, audio from APSS is about 10 hertz, below the range of human hearing.

The raw audio sample from the seismometer was released unaltered; a second version was raised two octaves to be more perceptible to the human ear — especially when heard through laptop or mobile speakers. The second audio sample from APSS was sped up by a factor of 100, which shifted it up in frequency.

An even clearer sound from Mars is yet to come. In just a couple years, NASA’s Mars 2020 rover is scheduled to land with two microphones on board. The first, provided by JPL, is included specifically to record, for the first time, the sound of a Mars landing. The second is part of the SuperCam and will be able to detect the sound of the instrument’s laser as it zaps different materials. This will help identify these materials based on the change in sound frequency.

JPL manages InSight for NASA’s Science Mission Directorate in Washington. InSight is part of NASA’s Discovery Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including CNES and the German Aerospace Center, support the InSight mission. CNES and the Institut de Physique du Globe de Paris provided SEIS, with significant contributions from the Max Planck Institute for Solar System Research in Germany, the Swiss Institute of Technology in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package HP³ instrument, with significant contributions from the Space Research Center of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología supplied the wind sensors.

Los Alamos National Laboratory in New Mexico and Institut de Recherche en Astrophysique et Planétologie in France are responsible for delivering the SuperCam instrument to NASA. The SuperCam microphone is provided by Institut Supérieur de l’Aéronautique et de l’Espace, a French higher education institution.

For more information about InSight, visit:

https://www.nasa.gov/insight

With a reach of nearly 6 feet (2 meters), the arm will be used to pick up science instruments from the lander’s deck, gently setting them on the Martian surface at Elysium Planitia, the lava plain where InSight touched down on Nov. 26.

But first, the arm will use its Instrument Deployment Camera, located on its elbow, to take photos of the terrain in front of the lander. These images will help mission team members determine where to set InSight’s seismometer and heat flow probe — the only instruments ever to be robotically placed on the surface of another planet.

“Today we can see the first glimpses of our workspace,” said Bruce Banerdt, the mission’s principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By early next week, we’ll be imaging it in finer detail and creating a full mosaic.”

Another camera, called the Instrument Context Camera, is located under the lander’s deck. It will also offer views of the workspace, though the view won’t be as pretty.

“We had a protective cover on the Instrument Context Camera, but somehow dust still managed to get onto the lens,” said Tom Hoffman of JPL, InSight’s project manager. “While this is unfortunate, it will not affect the role of the camera, which is to take images of the area in front of the lander where our instruments will eventually be placed.”

Placement is critical, and the team is proceeding with caution. Two to three months could go by before the instruments have been situated and calibrated.

Over the past week and a half, mission engineers have been testing those instruments and spacecraft systems, ensuring they’re in working order. A couple instruments are even recording data: a drop in air pressure, possibly caused by a passing dust devil, was detected by the pressure sensor. This, along with a magnetometer and a set of wind and temperature sensors, are part of a package called the Auxiliary Payload Sensor Subsystem, which will collect meteorological data.

More images from InSight’s arm were scheduled to come down this past weekend. However, imaging was momentarily interrupted, resuming the following day. During the first few weeks in its new home, InSight has been instructed to be extra careful, so anything unexpected will trigger what’s called a fault. Considered routine, it causes the spacecraft to stop what it is doing and ask for help from operators on the ground.

“We did extensive testing on Earth. But we know that everything is a little different for the lander on Mars, so faults are not unusual,” Hoffman said. “They can delay operations, but we’re not in a rush. We want to be sure that each operation that we perform on Mars is safe, so we set our safety monitors to be fairly sensitive initially.”

Spacecraft engineers had already factored extra time into their estimates for instrument deployment to account for likely delays caused by faults. The mission’s primary mission is scheduled for two Earth years, or one Mars year — plenty of time to gather data from the Red Planet’s surface.

About InSight

JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and the Institut de Physique du Globe de Paris (IPGP) provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP³) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.

For more information about InSight, visit:

https://mars.nasa.gov/insight/

Generations of planetary scientists will get to study pieces of the primitive materials that formed our cosmic neighborhood and to better understand the role asteroids may have played in delivering life-forming compounds to planets and moons.

But it’s not just history that the mission to Bennu will help uncover. Scientists studying the rock through OSIRIS-REx’s instruments in space will also shape our future. As they collect the most detailed information yet about the forces that move asteroids, experts from NASA’s Planetary Defense Coordination Office, who are responsible for detecting potentially hazardous asteroids, will improve their predictions of which ones could be on a crash-course with our planet.

Here is how the OSIRIS-REx mission will support this work:

How scientists predict Bennu’s whereabouts

About a third of a mile, or half a kilometer, wide, Bennu is large enough to reach Earth’s surface; many smaller space objects, in contrast, burn up in our atmosphere. If it impacted Earth, Bennu would cause widespread damage. Asteroid experts at the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory in Pasadena, California, project that Bennu will come close enough to Earth over the next century to pose a 1 in 2,700 chance of impacting it between 2175 and 2196. Put another way, those odds mean there is a 99.963 percent chance the asteroid will miss the Earth. Even so, astronomers want to know exactly where Bennu is located at all times.

Astronomers have estimated Bennu’s future trajectory after observing it several times since it was discovered in 1999. They’ve turned their optical, infrared and radio telescopes toward the asteroid every time it came close enough to Earth, about every six years, to deduce features such as its shape, rotation rate and trajectory.

“We know within a few kilometers where Bennu is right now,” said Steven Chesley, senior research scientist at CNEOS and an OSIRIS-REx team member whose job it is to predict Bennu’s future trajectory.

Why Bennu’s future trajectory predictions get fuzzy

Scientists have estimated Bennu’s trajectory around the Sun far into the future. Their predictions are informed by ground observations and mathematical calculations that account for the gravitational nudging of Bennu by the Sun, the Moon, planets and other asteroids, plus non-gravitational factors.

Given these parameters, astronomers can predict the next four exact dates (in September of 2054, 2060, 2080 and 2135) that Bennu will come within 5 million miles (7.5 million kilometers or .05 astronomical units) of Earth. That’s close enough that Earth’s gravity will slightly bend Bennu’s orbital path as it passes by. As a result, the uncertainty about where the asteroid will be each time it loops back around the Sun will grow, causing predictions about Bennu’s future orbit to become increasingly hazy after 2060.

In 2060, Bennu will pass Earth at about twice the distance from here to the Moon. But it could pass at any point in a 19-mile (30-kilometer) window of space. A very small difference in position within that window will get magnified enormously in future orbits and make it increasingly hard to predict Bennu’s trajectory.

As a result, when this asteroid comes back near Earth in 2080, according to Chesley’s calculations, the best window we can get on its whereabouts is nearly 9,000 miles (14,000 kilometers) wide. By 2135, when Bennu’s shifted orbit is expected to bring it closer than the Moon, its flyby window grows wider, to nearly 100,000 miles (160,000 kilometers). This will be Bennu’s closest approach to Earth over the five centuries for which we have reliable calculations.

“Right now, Bennu has the best orbit of any asteroid in our database,” Chesley said. “And yet, after that encounter in 2135, we really can’t say exactly where it is headed.”

There’s another phenomenon nudging Bennu’s orbit and muddying future impact projections. It’s called the Yarkovsky effect. Having nothing to do with gravity, the Yarkovsky effect sways Bennu’s orbit because of heat from the Sun.

“There are a lot of factors that might affect the predictability of Bennu’s trajectory in the future, but most of them are relatively small,” says William Bottke, an asteroid expert at the Southwest Research Institute in Boulder, Colorado, and a participating scientist on the OSIRIS-REx mission. “The one that’s most sizeable is Yarkvovsky.”

This heat nudge was named after the Polish civil engineer who first described it in 1901: Ivan Osipovich Yarkovsky. He suggested that sunlight warms one side of a small, dark asteroid and some hours later radiates that heat away as the asteroid rotates its hot side into cold darkness. This thrusts the rock pile a bit, either toward the Sun or away from it, depending on the direction of its rotation.

In Bennu’s case, astronomers have calculated that the Yarkovsky effect has shifted its orbit about 0.18 miles (284 meters) per year toward the Sunsince 1999. In fact, it helped deliver Bennu to our part of the solar system, in the first place, from the asteroid belt between Mars and Jupiter over billions of years. Now, Yarkovsky is complicating our efforts to make predictions about Bennu’s path relative to Earth.

Getting face-to-face with the asteroid will help

The OSIRIS-REx spacecraft will use its suite of instruments to transmit radio tracking signals and capture optical images of Bennu that will help NASA scientists determine its precise position in the solar system and its exact orbital path. Combined with existing, ground-based observations, the space measurements will help clarify how Bennu’s orbit is changing over time.

Additionally, astronomers will get to test their understanding of the Yarkovksy effect on a real-life asteroid for the first time. They will instruct the spacecraft to follow Bennu in its orbit about the Sun for about two years to see whether it’s moving along an expected path based on gravity and Yarkovsky theories. Any differences between the predictions and reality could be used to refine models of the Yarkovsky effect.

But even more significant to understanding Yarkovsky better will be the thermal measurements of Bennu. During its mission, OSIRIS-REx will track how much solar heat radiates off the asteroid, and where on the surface it’s coming from-data that will help confirm and refine calculations of the Yarkovsky effect on asteroids.

The spacecraft also will address some open questions about the Yarkovsky theory. One of them, said Chesley, is how do boulders and craters on the surface of an asteroid change the way photons scatter off of it as it cools, carrying away momentum from the hotter side and thereby nudging the asteroid in the opposite direction? OSIRIS-REx will help scientists understand by mapping the rockiness of Bennu’s surface.

“We know surface roughness is going to affect the Yarkovsky effect; we have models” said Chesley. “But the models are speculative. No one has been able to test them.”

After the OSIRIS-REx mission, Chesley said, NASA’s trajectory projections for Bennu will be about 60 times better than they are now.

Hydrogen bonds are among the most fundamental interactions found in biology and chemistry. They are responsible for many of the chemically important properties of water, for the stabilizing the structures of proteins and nucleic acids, including those found in DNA and RNA, and contribute to the structure of natural and synthetic polymers.

Research has shown that hydrogen bonds play an important role in tuning the reactivity of the metal centers of metalloenzymes and metal containing catalysts. However, little research has been done to experimentally demonstrate how systematic changes to hydrogen bonds within the secondary coordination sphere — molecules found in the vicinity of metal centers that do not have direct bonding interactions with the center — influence catalytic activity.

In catalysis, enzymes or synthetic catalysts spur on a chain of chemical reactions, which produce a number of intermediate structures or species. Understanding those structures and their chemical properties is key to understanding the entire reaction.

“Thoroughly understanding the chemical reactivity of the reactive intermediate is a key step to determining how to design highly efficient and selective catalysts for C-H functionalization,” said Yisong Guo, assistant professor of chemistry at Carnegie Mellon and the study’s lead author. “In the case of dioxygen-activating enzymes, the key intermediates of catalysis are iron-oxo (Fe-O) and iron-hydroxo (Fe-OH) species, which are involved in important biological processes, such as DNA biosynthesis, DNA and RNA repair, post-translational modification of proteins, biosynthesis of antibiotics and degradation of toxic compounds.”

Guo and colleagues used 57Fe nuclear resonance vibrational spectroscopy (NRVS), a newly developed synchrotron radiation-based technique, to detect the vibrational frequency of Fe-O and Fe-OH units of synthetic complexes that interact with the secondary coordination sphere through hydrogen bonds. Changes in the frequencies revealed valuable information about the bond strengths of these units and further provided a qualitative measure of hydrogen bond strength.

“This showed that NRVS is a sensitive technique to pick up very small changes in hydrogen bond strength, down to the changes of a single hydrogen bond. This provides us with a new method to connect changes in bond strength of Fe-O and Fe-OH units to their chemical reactivity,” said Guo.

Guo says that this study is a proof-of-concept for using NRVS to probe hydrogen bonds. He plans to continue using this method to study more iron-oxo and iron-hydroxo species in both synthetic complexes and enzymes to build up the amount of available data to correlate chemical reactivity of these species with the changes of hydrogen bond interactions, with the hope that that information could be used to develop more efficient and effective catalysts.

Story Source:

Materials provided by Carnegie Mellon University. Note: Content may be edited for style and length.

Spin-orbit coupling, the coupling of the qubits’ orbital and spin degree of freedom, allows the manipulation of the qubit via electric, rather than magnetic-fields. Using the electric dipole coupling between qubits means they can be placed further apart, thereby providing flexibility in the chip fabrication process.

In one of these approaches, published in Science Advances, a team of scientists led by UNSW Professor Sven Rogge investigated the spin-orbit coupling of a boron atom in silicon.

“Single boron atoms in silicon are a relatively unexplored quantum system, but our research has shown that spin-orbit coupling provides many advantages for scaling up to a large number of qubits in quantum computing” says Professor Rogge, Program Manager at the Centre for Quantum Computation and Communication Technology (CQC2T).

Following on from earlier results from the UNSW team, published last month in Physical Review X, Rogge’s group has now focused on applying fast read-out of the spin state (1 or 0) of just two boron atoms in an extremely compact circuit all hosted in a commercial transistor.

“Boron atoms in silicon couple efficiently to electric fields, enabling rapid qubit manipulation and qubit coupling over large distances. The electrical interaction also allows coupling to other quantum systems, opening up the prospects of hybrid quantum systems,” says Rogge.

Another piece of recent research by Professor Michelle Simmons’ team at UNSW has also highlighted the role of spin orbit coupling in atom-based qubits in silicon, this time with phosphorus atom qubits. The research was recently published in npj Quantum Information.

The research revealed surprising results. For electrons in silicon — and in particular those bound to phosphorus donor qubits — spin orbit control was commonly regarded as weak, giving rise to seconds long spin lifetimes. However, the latest results revealed a previously unknown coupling of the electron spin to the electric fields typically found in device architectures created by control electrodes.

“By careful alignment of the external magnetic field with the electric fields in an atomically engineered device, we found a means to extend these spin lifetimes to minutes,” says Professor Michelle Simmons, Director, CQC2T.

“Given the long spin coherence times and the technological benefits of silicon, this newly discovered coupling of the donor spin with electric fields provides a pathway for electrically-driven spin resonance techniques, promising high qubit selectivity,” says Simmons.

Both results highlight the benefits of understanding and controlling spin orbit coupling for large-scale quantum computing architectures.

Commercialising silicon quantum computing IP in Australia

Since May 2017, Australia’s first quantum computing company, Silicon Quantum Computing Pty Limited (SQC), has been working to create and commercialise a quantum computer based on a suite of intellectual property developed at the Australian Centre of Excellence for Quantum Computation and Communication Technology (CQC2T). Its goal is to produce a 10-qubit prototype device in silicon by 2022 as the forerunner to a commercial scale silicon-based quantum computer.

As well as developing its own proprietary technology and intellectual property, SQC will continue to work with CQC2T and other participants in the Australian and International Quantum Computing ecosystems, to build and develop a silicon quantum computing industry in Australia and, ultimately, to bring its products and services to global markets.

The report is particularly worthy of attention for the following reasons.

First, ETRI’s free-space QKD system works successfully even during the daylight whereas most other systems have failed to operate properly due to substantial amount of noise photons from sunlight. By developing and adopting elaborate noise filtering technologies, ETRI’s QKD system achieved the secure key rate of 142.94 kbps with quantum bit error rate of 4.26% in daylight over the free-space distance of 275 m.

Second, ETRI’s QKD system is configured with the self-developed polarization encoding chip, which dramatically reduces the size of the system compared to conventional QKD systems. Miniaturizing key components is highly important to make QKD systems to be used for the secure communication solution of several applications requiring light-weight such as Unmanned Aircraft Vehicle (UAV) and automotive cars, whose security is one of the critical concerns. The chip-based QKD component of ETRI is considered as a core technology for the commercialization of QKD system in various fields.

ETRI is now applying their integrated-chip technologies to other optical components to realize miniaturized QKD transceiver modules. Also, ETRI is trying to conduct the free-space QKD experiments for the extended transmission distance in daylight.

Story Source:

Materials provided by National Research Council of Science & Technology. Note: Content may be edited for style and length.

But the production methods based on extracts from natural resources are environmentally damaging and often give rise to extensive piles of chemical waste. In addition, there is a great danger that these rare plants will go extinct. The need to find new and more sustainable production methods for these types of medicines has grown since the UN recently adopted new regulations to protect biodiversity and raw materials in third world countries.

“With these new rules, a real alternative is needed if we wish to be able to produce therapeutics to cancer patients or people suffering from mental illnesses in the future,” says Senior Researcher at The Novo Nordisk Foundation Center for Biosustainability. He is the coordinator of a new big EU Horizon 2020 project called MIAMi, which has just received a grant of 6 million Euro.

Indian snakeroot may be the solution

In many cases, these very complex plant chemicals can’t be synthesized chemically like ‘normal’ pharmaceuticals — it simply has to be a bio-catalytic process.

The aim of the MIAMi research project is to provide the pharmaceutical industry with an alternative production route using the cellular workhorse baker’s yeast. To start with, the researchers want to map the so-called biosynthetic pathways of the rare plant Rauvolfia serpentina with the common name Indian snakeroot.

From traditional Chinese medicine, it is known that Indian snakeroot produces molecules with anticancer effect. However, manufacturing the valuable compounds outside the plant is still not possible, because the biosynthetic pathways are unknown.

In short, a biosynthetic pathway is a number of specific genes that code for enzymes, which synthesize a bio-molecule within the cell. Knowing the genetic “route” of the product, makes it possible to move the genes into, for instance, baker’s yeast. The goal is to insert the genes into yeast cells that will act as biological cell factories capable of producing large amounts of these specific therapeutic substances.

Regulations push the industry

One of the partners of MIAMi is the French chemical company Axyntis, which annually imports hundreds of tonnes of plant seed to extract substances for further production of medicine such as tabersonine from the rare plant Voacanga africana. However, the new legislation limits this way of producing medicine.

“The industry knows that they need to change, which these regulations are also a clear signal about. We do not expect to be able to manufacture the products within this project period so that they can compete with current processes, but the alternative is that companies in the future can’t offer the same products to their customers,” says Michael Krogh Jensen.

Over the past 20-30 years, the shelves of bioactive substances in the company’s “chemical libraries” have gradually been used up, and the industry is now in great need of new drugs against new and existing diseases. Therefore, there is also a need to discover new natural occurring molecules with activity against some of the major public diseases such as cancer and mental illness, for example, schizophrenia. Another focus is, therefore, to find new and unknown plant molecules. The project runs for a 4-year period.

Story Source:

Materials provided by Technical University of Denmark. Note: Content may be edited for style and length.

“Imagine you are in a world where electrons are colored — red or blue,” Zhu said, “and the roads that electrons travel on are also colored red or blue. Electrons are only allowed to travel on roads of the same color, so that a blue electron would have to turn into a red electron to travel on the red road.”

Two years ago, Zhu’s team showed that they could build color-coded, two-way roads in a material called bilayer graphene. Because of their color-coding, these roads are topological. In the current study, the researchers made a four-way intersection where the color-coding of the roads is switched on the other side. Therefore, you have a situation where a blue car traveling northbound comes to this intersection and discovers that on the other side of the intersection northbound roads are colored red. If the electron cannot change color, it is forbidden from traveling onward.

These roads are actually electron waveguides created by gates defined with extreme precision using state-of-the-art electron beam lithography. The colors are actually the valley index of the cars, and the color-coding of the roads is controlled by the topology of the waveguides, analogous to the left-driving and right-driving rules of different countries. Changing the color of the cars requires “inter-valley scattering,” which is minimized in the experiment to enable the traffic control to work.

“What we have achieved here is a topological valley valve, which uses a new mechanism to control electron flow,” Zhu said. “This is part of a fledging field of electronics called valleytronics. In our experiment, controlling the topology — the valley-momentum locking of the electrons — is what made it work.”

In the study, the researchers asked where would the metaphorical blue car go if it could not travel onward?

“It will have to turn either left or right,” said lead author Jing Li, Zhu’s former doctoral student, now a director’s postdoctoral fellow at Los Alamos National Lab.

“We have additional ways of controlling the turning traffic — by moving the lane incrementally closer to a right or left turn, the percentage of electrons/cars turning right or left can be smoothly tuned to be 60 percent one way, 40 percent the other, or any other combination of percentages.”

This controlled partition is called a “beam splitter,” which is common for light but not easily accomplished with electrons. Zhu and Li said they are excited about this control they have achieved for their color-coded roadways, as it enables more advanced experiments down the road.

“The creation of the device requires many steps and fairly complicated e-beam lithography,” Li said. “Thankfully, Penn State’s state-of-the art nanofabrication facility as well as a team of professional support staff enabled us to do all this.”

The next challenge for Zhu’s team will be to try to build their devices to operate at room temperature rather than at the very cold temperatures they currently need. It is doable, Zhu believes, but challenging.

“The approach we took to make this device is scalable,” Zhu said. “If large-area bilayer graphene and hexagonal boron nitride become available, we can potentially make a city of topological roads and shuttle electrons to places they need to go, all without resistance. That would be very cool.”

Story Source:

Materials provided by Penn State. Note: Content may be edited for style and length.