Showing posts with label MIT. Show all posts
Showing posts with label MIT. Show all posts

Sunday, August 2, 2020

MIT advances quantum information sharing between processors

Researchers at MIT are developing an on-off system that leverages "giant atoms" to enable high-fidelity operations and interconnection between processors.

A key challenge in quantum computing has been to communicate quantum information between distant parts of a processor.

In a paper published in the journal Nature, the MIT researchers constructed “giant artificial atoms” from superconducting quantum bits, or qubits, connected in a tunable configuration to a microwave transmission line, or waveguide.

“Coupling a qubit to a waveguide is usually quite bad for qubit operations, since doing so can significantly reduce the lifetime of the qubit,” says Bharath Kannan, MIT graduate fellow and first author of the paper. “However, the waveguide is necessary in order to release and route quantum information throughout the processor. Here, we’ve shown that it’s possible to preserve the coherence of the qubit even though it’s strongly coupled to a waveguide. We then have the ability to determine when we want to release the information stored in the qubit. We have shown how giant atoms can be used to turn the interaction with the waveguide on and off.”

Sunday, July 12, 2020

MIT's “Light squeezer” reduces quantum noise in lasers

Researchers at MIT have developed a quantum “light squeezer” that reduces quantum noise in an incoming laser beam by 15%.

The portable light squeezer works at room temperature and could be used to improve laser measurements where quantum noise is a limiting factor. The setup is based on a marble-sized optical cavity, housed in a vacuum chamber and containing two mirrors, the first of which is smaller than the diameter of a human hair. The second, larger, nanomechanical mirror, which suspended by a spring-like cantileve, is the key to the system’s ability to work at room temperature.

“The importance of the result is that you can engineer these mechanical systems so that at room temperature, they still can have quantum mechanical properties,” says Nergis Mavalvala, the Marble Professor and associate head of physics at MIT. “That changes the game completely in terms of being able to use these systems, not just in our own labs, housed in large cryogenic refrigerators, but out in the world.”

Wednesday, July 8, 2020

MIT: Scaling up the quantum chip

Researchers at MIT have achieved a breakthrough in the field of scalable quantum processors by developing a process to manufacture and integrate “artificial atoms,” created by atomic-scale defects in microscopically thin slices of diamond, with photonic circuitry.

A team, led by Dirk Englund, an associate professor in MIT’s Department of Electrical Engineering and Computer Science, were able to build a 128-qubit system — the largest integrated artificial atom-photonics chip to date. The hybrid manufacturing approach iused carefully selected “quantum micro chiplets” containing multiple diamond-based qubits placed on an aluminum nitride photonic integrated circuit.

“In the past 20 years of quantum engineering, it has been the ultimate vision to manufacture such artificial qubit systems at volumes comparable to integrated electronics,” Englund says. “Although there has been remarkable progress in this very active area of research, fabrication and materials complications have thus far yielded just two to three emitters per photonic system.”

Sunday, August 18, 2019

MIT researchers target “risk-aware” cloud traffic engineering

Researchers at MIT, working in collaboration with Microsoft, have developed a “risk-aware” mathematical model for improving the performance and resiliency of cloud infrastructure.

The model takes into account failure probabilities of links between data centers worldwide and then allocates traffic through optimal paths to minimize loss, while maximizing overall usage of the network.

The researchers believe their model can deliver three times the traffic throughput compared to traditional traffic-engineering while maintaining the same high level of network availability.

Sunday, August 19, 2018

MIT: Lincoln Lab looks to narrow-beam lasers for underwater comms

Researchers at Lincoln Laboratory are investigating laser technology for underwater communications. The work builds on the Lunar Laser Communication Demonstration (LLCD) project conducted with NASA, which successfully transmitted data from a satellite orbiting the moon to Earth at 622 Mbps.

Researchers are using narrow-beam optics to help overcome the significant absorption and scattering effects of water.

This technique contrasts with the more common undersea communication approach that sends the transmit beam over a wide angle but reduces the achievable range and data rate. “By demonstrating that we can successfully acquire and track narrow optical beams between two mobile vehicles, we have taken an important step toward proving the feasibility of the laboratory’s approach to achieving undersea communication that is 10,000 times more efficient than other modern approaches,” says Scott Hamilton, leader of the Optical Communications Technology Group, which is directing this R&D into undersea communication.

Sunday, August 5, 2018

MIT researchers develop silicon-based optical filter

Researchers from MIT’s Research Laboratory of Electronic have designed an optical filter on a chip that can process optical signals from across an extremely wide spectrum of light at once.

“This new filter takes an extremely broad range of wavelengths within its bandwidth as input and efficiently separates it into two output signals, regardless of exactly how wide or at what wavelength the input is. That capability didn’t before in integrated optics,” says Emir Salih Magden, a former PhD student in MIT’s Department of Electrical Engineering and Computer Science (EECS) and first author on a paper describing the filters published today in Nature Communications.

Potential applications include fiber-to-the-home installations.

Monday, April 23, 2018

MIT: a new technique for assembling on-chip optics and electronics separately

A team of researchers led by groups at MIT, the University of California at Berkeley, and Boston University, have developed a technique for assembling on-chip optics and electronics separately using existing manufacturing processes.

The work, which is described in an article in the latest issue of Nature, allows the addition of optical communication components onto chips with modern transistors.

“The most promising thing about this work is that you can optimize your photonics independently from your electronics,” says Amir Atabaki, a research scientist at MIT’s Research Laboratory of Electronics and one of three first authors on the new paper. “We have different silicon electronic technologies, and if we can just add photonics to them, it’d be a great capability for future communications and computing chips. For example, now we could imagine a microprocessor manufacturer or a GPU manufacturer like Intel or Nvidia saying, ‘This is very nice. We can now have photonic input and output for our microprocessor or GPU.’ And they don’t have to change much in their process to get the performance boost of on-chip optics.”

Sunday, January 14, 2018

MIT News: New exotic phenomena seen in photonic crystals

Researchers at MIT have observed a new topological phenomena in photonic crystals that could open up some new realms of basic physics research, according to the university. A paper on the topic has been published in the journal Science.

Whereas previous research has focused on closed, Hermitian systems, this research examines open system where energy or material can enter or be emitted. One of the observed effects in the photonic crystal is an unusual kind of changing polarization of light waves.

Saturday, August 2, 2014

MIT: Light Pulses Control Graphene’s Electrical Behavior

Researchers at MIT have developed a method of using light pulses to control the electrical properties of a sheet of graphene. Short light pulses were found to change and reveal graphene’s electrical response in only a trillionth of a second.

The discovery by graduate student Alex Frenzel, Nuh Gedik, and three others, could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors.

The findings have now been published in the journal Physical Review Letters.  MIT also noted that the work received support from the U.S. Department of Energy and the National Science Foundation.

Thursday, July 17, 2014

MIT's Fastpass Promises to Cut Data Center Latency

Researchers at MIT are developing a "Fastpass" network management system that promises to significantly reduce the latency between servers in hyperscale data centers.

According to a university blog, the MIT Fastpass system uses a central server called an "arbiter" to decide which nodes in the data center network may send data to other nodes in a designated time slot.  An arbiter based on the latest multicore silicon reportedly can keep up with a network carrying over 2 terabits of traffic.  The article estimates the system could reduce
latency in a Facebook data center by 99%.

The MIT researchers plans to present their work at an upcoming conference in August.