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Related News: Quantum Computing and Information Science

The race to build larger and larger quantum computers is heating up, with several technologies competing for a role in future devices. Each potential platform has strengths and weaknesses, but little has been done to directly compare the performance of early prototypes. Now, researchers at the JQI have performed a first-of-its-kind benchmark test of two small quantum computers built from...

Consider, for a moment, the humble puddle of water. If you dive down to nearly the scale of molecules, it will be hard to tell one spot in the puddle from any other. You can shift your gaze to the left or right, or tilt your head, and the microscopic bustle will be identical—a situation that physicists call highly symmetric.That all changes abruptly when the puddle freezes. In contrast to...

From credit card numbers to bank account information, we transmit sensitive digital information over the internet every day. Since the 1990s, though, researchers have known that quantum computers threaten to disrupt the security of these transactions. That’s because quantum physics predicts that these computers could do some calculations far faster than their conventional counterparts. This...

The 2015 discovery of a Weyl semimetal—and the Weyl fermions it harbored—provoked a flurry of activity from researchers around the globe. A quick glance at a recent physics journal or the online arXiv preprint server testifies to the topic’s popularity. The arXiv alone has had more than 200 papers on Weyl semimetals posted in 2016.Researchers at JQI and the Condensed Matter Theory Center (CMTC...

For decades, particle accelerators have grabbed headlines while smashing matter together at faster and faster speeds. But in recent years, alongside the progress in high-energy experiments, another realm of physics has been taking its own exciting strides forward.That realm, which researchers call condensed matter physics, studies chunks of matter moving decidedly slower than the protons in...

When it comes to quantum physics, light and matter are not so different. Under certain circumstances, negatively charged electrons can fall into a coordinated dance that allows them to carry a current through a material laced with imperfections. That motion, which can only occur if electrons are confined to a two-dimensional plane, arises due to a phenomenon known as the quantum Hall effect....

Today’s networks use electronic circuits to store information and optical fibers to carry it, and quantum networks may benefit from a similar framework. Such networks would transmit qubits – quantum versions of ordinary bits – from place to place and would offer unbreakable security for the transmitted information. But researchers must first develop ways for qubits that are better at storing...

Harnessing quantum systems for information processing will require controlling large numbers of basic building blocks called qubits. The qubits must be isolated, and in most cases cooled such that, among other things, errors in qubit operations do not overwhelm the system, rendering it useless. Led by JQI Fellow Christopher Monroe, physicists have recently demonstrated important steps towards...

The concept of temperature is critical in describing many physical phenomena, such as the transition from one phase of matter to another. Turn the temperature knob and interesting things can happen. But other knobs might be just as important for studying some phenomena. One such knob is chemical potential, a thermodynamic parameter first introduced in the nineteenth century by scientists for...

The quantum Hall effect, discovered in the early 1980s, is a phenomenon that was observed in a two-dimensional gas of electrons existing at the interface between two semiconductor layers. Subject to the severe criteria of very high material purity and very low temperatures, the electrons, when under the influence of a large magnetic field, will organize themselves into an ensemble state...

In quantum mechanics, symmetry describes more than just the patterns that matter takes — it is used to classify the nature of quantum states. These states can be entangled, exhibiting peculiar connections that cannot be explained without the use of quantum physics. For some entangled states, the symmetry of these connections can offer a kind of protection against disruptions. Physicists are...

Rydberg atoms, atoms whose outermost electrons are highly excited but not ionized, are potentially important for storing an processing quantum information since they can preserve a superpostion of states for a long time. One problem with Rydberg atoms is that in they are often difficult to handle. One approach is to search for special wavelengths---“magic wavelengths”—at which atoms can be...

If you’re designing a new computer, you want it to solve problems as fast as possible. Just how fast is possible is an open question when it comes to quantum computers, but JQI physicists have narrowed the theoretical limits for where that “speed limit” is. The work implies that quantum processors will work more slowly than some research has suggested. 
The work offers a better...

JQI researchers, under the direction of Christopher Monroe have demonstrated modular entanglement between two atomic systems, separated by one meter. Here, photons are the long distance information carriers entangling multiple qubit modules. Inside of a single module, quantized collective vibrations called phonons connect individual qubits. In the latest result, one module contains two qubits...

In quantum mechanics, interactions between particles can give rise to entanglement, which is a strange type of connection that could never be described by a non-quantum, classical theory. These connections, called quantum correlations, are present in entangled systems even if the objects are not physically linked (with wires, for example). Entanglement is...

Physicists led by ion-trapper Christopher Monroe at the JQI have proposed a modular quantum computer architecture that promises scalability to much larger numbers of qubits. The components of this architecture have individually been tested and are available, making it a promising approach. In the paper, the authors present expected performance and scaling calculations, demonstrating that their...

Unfortunately, qubits are fragile; they dissipate in the face of interactions with their environment. A new JQI semiconductor-based qubit design ably addresses this issue of qubit robustness.

JQI researchers in the lab of Alan Migdall, demonstrate how one category of photo-detection system can make highly accurate readings of incoming information at the single-photon level by allowing the detector in some instances not to give a conclusive answer.

The sequence of images that constitute Hollywood movies can be stored handily on solid-state media such as magnetic tape or compact diskettes. At the JQI images can be stored in something as insubstantial as a gas of rubidium atoms.

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Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...

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