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Physics Frontier Center

About the PFC @ JQI

The Physics Frontier Center is devoted to leading-edge experimental and theoretical investigation of ways to control and process quantum coherence and entanglement: the physics of quantum information. It is funded through a cooperative agreement with the National Science Foundation (NSF) and operated within the Joint Quantum Institute (JQI), a partnership between the University of Maryland (UMD) and the National Institute of Standards and Technology (NIST), with additional support from the Laboratory for Physical Sciences.

September 17, 2018 | PFC | Research News

Modified superconductor synapse reveals exotic electron behavior

Electrons tend to avoid one another as they go about their business carrying current. But certain devices, cooled to near zero temperature, can coax these loner particles out of their shells. In extreme cases, electrons will interact in unusual ways, causing strange quantum entities to emerge.

August 2, 2018 | Research News |PFC

Complexity test offers new perspective on small quantum computers

State-of-the-art quantum devices are not yet large enough to be called full-scale computers. The biggest comprise just a few dozen qubits—a meager count compared to the billions of bits in an ordinary computer’s memory. But steady progress means that these machines now routinely string together 10 or 20 qubits and may soon hold sway over 100 or more.

July 5, 2018 | Research News |PFC

Semiconductor quantum transistor opens the door for photon-based computing

Transistors are tiny switches that form the bedrock of modern computing—billions of them route electrical signals around inside a smartphone, for instance.

Quantum computers will need analogous hardware to manipulate quantum information. But the design constraints for this new technology are stringent, and today’s most advanced processors can’t be repurposed as quantum devices. That’s because quantum information carriers, dubbed qubits, have to follow different rules laid out by quantum physics. 

June 28, 2018 | Research News |PFC

Quantum gas reveals first signs of path-bending monopole

Magnets, whether in the form of a bar, horseshoe or electromagnet, always have two poles. If you break a magnet in half, you’ll end up with two new magnets, each with its own magnetic north and south.

But some physics theories predict the existence of single-pole magnets—a situation akin to electric charges, which come in either positive or negative chunks. One particular incarnation—called the Yang monopole after its discoverer—was originally predicted in the context of high-energy physics, but it has never been observed. 

May 8, 2018 | People News |PFC

Eliot Fenton recognized as a Maryland ‘Undergraduate Researcher of the Year’

Eliot Fenton, UMD physics major, was among those recognized as a 2018 Maryland ‘Undergraduate Researcher of the Year.’ This award is eligible for exemplary seniors who have been nominated by their faculty advisors.  Fenton earned this award for his wide-ranging experimental physics research accomplishments.

April 23, 2018 | People News |PFC

JQI alumnus Pablo Solano awarded dissertation prize

Pablo Solano, a recent graduate student with JQI Fellow and UMD physics professor Luis Orozco, has been awarded the Charles A. Caramello Distinguished Dissertation Prize. According to the official award description, the prize recognizes “original work that makes an unusually significant contribution to its discipline.” The prize is given in four broad disciplinary areas and comes with an honorarium.

April 19, 2018 | Research News |PFC

Atoms may hum a tune from grand cosmic symphony

Researchers playing with a cloud of ultracold atoms uncovered behavior that bears a striking resemblance to the universe in microcosm. Their work, which forges new connections between atomic physics and the sudden expansion of the early universe, was published April 19 in Physical Review X and featured in Physics.

March 28, 2018 | Research News |PFC

Latest nanowire experiment boosts confidence in Majorana sighting

In the latest experiment of its kind, researchers have captured the most compelling evidence to date that unusual particles lurk inside a special kind of superconductor. The result, which confirms theoretical predictions first made nearly a decade ago at the Joint Quantum Institute (JQI) and the University of Maryland (UMD), will be published in the April 5 issue of Nature

March 13, 2018 | Research News |PFC

Two-toned light pattern creates steep quantum walls for atoms

Exotic physics can happen when quantum particles come together and talk to each other. Understanding such processes is challenging for scientists, because the particle interactions can be hard to glimpse and even harder to control. Moreover, modern computer simulations struggle to make sense of all the intricate dynamics going on in a large group of particles. Luckily, atoms cooled to near zero temperatures can provide insight into this problem.

February 12, 2018 | Research News |PFC

New hole-punched crystal clears a path for quantum light

Optical highways for light are at the heart of modern communications. But when it comes to guiding individual blips of light called photons, reliable transit is far less common. Now, a collaboration of researchers from the Joint Quantum Institute (JQI), led by JQI Fellows Mohammad Hafezi and Edo Waks, has created a photonic chip that both generates single photons, and steers them around. The device, described in the Feb.

Brief Reports

A team of PFC-funded scientists from JQI has leveraged atoms’ inherent quantum features to allow neighbors in an atomic lattice to get closer than ever before. The new technique manages to squeeze the ordinary gentle hills of an... Read more

A collaboration of PFC-funded researchers from JQI has created a photonic chip that both generates single photons, and steers them around certain kinds of obstacles.

The chip starts with a photonic crystal, which is an established, versatile technology used to create roadways for light.... Read more

In the latest experiment of its kind, researchers have captured the most compelling evidence to date that unusual particles lurk inside a special kind of superconductor.

The stowaways, dubbed Majorana quasiparticles, are different from ordinary matter like electrons or quarks—the stuff... Read more

In several sets of experiments, PFC-funded researchers at JQI rapidly expanded the size of a doughnut-shaped cloud of atoms, taking snapshots during the process. The growth happens so fast that the cloud is left humming, and a related hum may have appeared on cosmic scales during the rapid... Read more

Solitons — solitary waves that behave more like discrete particles than waves — occur in diverse physical systems, from water in a canal to light waves in optical-fiber telecommunications. They can also exist in Bose-Einstein condensates, manifesting as stable density waves.

In a pristine... Read more

Only in quantum physics can traffic be standing still and moving at the same time.

A new paper from scientists at the National Institute of Standards and Technology (NIST) and the University of Maryland suggests that intentionally creating a traffic jam out of a ring of several thousand... Read more

Optical fibers are the backbone of modern communications, shuttling information from A to B through thin glass filaments as pulses of light. They are used extensively in telecommunications, allowing information to travel at near the speed of light virtually without loss. 

These days,... Read more

In 2012, Nobel-prize winning physicist Frank Wilczek, a professor at the Massachusetts Institute of Technology, proposed something that sounds pretty strange. It might be possible, Wilczek argued, to create crystals that are arranged in time instead of space. The suggestion prompted years of... Read more

Quantum computers promise speedy solutions to some difficult problems, but building large-scale, general-purpose quantum devices is a problem fraught with technical challenges.

In a paper published as the cover story in Nature on August 4, 2016, PFC-funded researchers introduced the first... Read more

Physical systems that retain no memory of their initial conditions are said to have thermalized, since it is often—but not always—an exchange of heat and energy with another system that causes the memory loss. The opposite case is localization, where information about the initial arrangement... Read more

Pumps have been around for millennia, but recently physicists have sought to build a different kind of pump—one that could use the rules of quantum mechanics to pump atoms or charges in a quantized way. PFC-supported researchers have created the first pump based on the geometry of quantum... Read more

Magnetic fields arise from the microscopic behavior of atoms and their electrons. In permanent magnets, neighboring atoms align and lock into place to create inseparable north and south poles. For other materials, magnetism can be induced by a field strong enough to coax atoms into alignment.... Read more

Rydberg atoms are a popular choice for quantum device proposals because they interact strongly with each other and their individual and collective behavior is easy to manipulate. While experimenting with rubidium, one of the most popular Rydberg systems, PFC-supported researchers discovered an... Read more

In the fractional quantum Hall (FQH) effect, the collective action of electrons in a material form particle-like “quasiparticles” that can appear to possess fractional charge, such as 1/3. In quantum Hall systems, these quasiparticles can become trapped around specially tailored defects, forming... Read more

Ultracold atomic systems can be used to model condensed-matter physics, providing precise control of system variables often not achievable in real materials. This involves inducing charge-neutral particles to behave as if they were charged particles in a magnetic field. To this end, PFC-... Read more

Particles can be classified as bosons or fermions. A defining characteristic of a boson is its ability to pile into a single quantum state with other bosons. Fermions are not allowed to do this. One broad impact of fermionic anti-social behavior is that it allows for carbon-based life forms,... Read more

PFC-supported researchers have used trapped atomic ions to construct a system that could potentially support a type of symmetry-protected quantum state. For this research they used a three-state system, called a qutrit, to demonstrate a proof-of-principle experiment for performing quantum... Read more

Optical nanofibers are optical fibers that have a diameter smaller than the wavelength of the guided light. Here, all of the light field cannot fit inside of the fiber, yielding a significant enhancement in the evanescent fields outside of the core. This allows the light to trap atoms (or other... Read more

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 PFC supported physicists have developed a new mathematical proof that reveals a much tighter limit on how fast quantum... Read more

The 2014 chemistry Nobel Prize recognized important microscopy research that enabled greatly improved spatial resolution. This innovation, resulting in nanometer resolution, was made possible by making the source (the emitter) of the illumination  quite small and by moving it quite close to the... Read more

Strongly correlated electronic systems, like superconductors, display remarkable electronic and magnetic properties. Creating analogous states in Bose gases is an excellent way to model the dynamics of these systems, offering a level of control often not possible in solid state systems.

... Read more

In certain situations, a collection of atoms can transition to a superfluid state, flouting the normal rules of liquid behavior. Harnessing this effect is of particular interest in the field of atomtronics, since superfluid atom circuits can recreate the functionality of superconductor circuits... Read more

Atom-optical lattice systems offer a clean, well-controlled way to study the manipulation and movement of spins because researchers can create particle configurations analogous to crystalline order in materials. PFC supported theorists have been developing a model for what happens when ultracold... Read more

Topological transport of light is the photonic analog of topological electron flow in certain semiconductors. In the electron case, the current flows around the edge of the material but not through the bulk. It is “topological” in that even if electrons encounter impurities in the material the... Read more

Atomtronics is an emerging technology whereby physicists use ensembles of atoms to build analogs to electronic circuit elements. Using a superfluid atomtronic circuit, PFC supported physicists have demonstrated a tool that is critical to electronics: hysteresis. This is the first time that... Read more

Can scientists generate any color of light? The answer is not really, but the invention of the laser in 1960 opened new doors for this endeavor. An early experiment injected high-power laser light through quartz and out popped a different color. This sparked the field of nonlinear optics and... Read more

Topology -- the understanding of how things are connected -- remains abstract, even with the popular example of doughnuts and coffee cups. This concept, esoteric as it appears, is also neat because it is the basis for creating ultrastable quantum "playgrounds."  In topological systems, certain... Read more

The photodetectors in Alan Migdall’s lab often see no light at all, and that’s a good thing since he and his JQI colleagues perform physics experiments that require very little light, the better to study subtle quantum effects. The bursts of light they observe typically consist of only one or... Read more

A JQI/PFC experiment establishes a new record for symmetric single-mode, single-photon, heralding efficiency for a pair of entangled photons produced during parametric downconversion. About 84% of the time they observe photon A in one detector they also observe photon B just where it should be... Read more

PFC researchers explored how to frustrate a quantum magnet comprised of sixteen atomic ions – to date the largest ensemble of qubits to perform a simulation of quantum matter.

Physicists engineer a quantum magnet using lasers and ion ... Read more

All computers, even the future quantum versions, use logic operations or “gates,” which are the fundamental building blocks of computational processes. PFC scientists have performed an ultrafast logic gate on a photon, using a semiconductor quantum dot.

Quantum dots are an attractive... Read more

Last year Paul Lett and his JQI colleagues reported the ability to store a sequence of images (two letters of the alphabet) which were separated in time but overlapping in space within the volume of a gas-filled memory cell. This is random access in time. In a new experiment, by contrast, parts... Read more

The blackbody radiation shift imposed by atom traps on the energy level of the enclosed ultracold atoms will soon impose limits on the accuracy of the best atomic clocks. Although only important at a precision level of a part in 1015, accurate knowledge of this shift is more pertinent now that... Read more

Physicists at the Joint Quantum Institute (JQI) and the University of Maryland show, for the first time, that qubits can successfully exist in a topological superconductor material even in the presence of impurities in the material and strong interactions among participating electrons, courtesy... Read more

Magnetic monopoles weren’t supposed to exist. If you try to saw a bar magnet in half, all you succeed in getting are two magnets, each with a south and north pole. In recent years, however, the existence of monopole quasiparticles consisting of collective excitations among many atoms has been... Read more

A PFC-supported experiment conducted at the Joint Quantum Institute examines the role of disorder in maintaining quantum coherence. It does this by introducing disorder into a Bose-Einstein condensate of rubidium atoms held in an optical lattice to simulate the role is impurity disorder in high... Read more

PFC-supported scientists have stored not one but two letters of the alphabet in a tiny cell filled with rubidium atoms which are tailored to absorb and later re-emit messages on demand. This is the first time two images have simultaneously been reliably stored in a non-solid medium and then... Read more

PFC-supported experimentalists have developed a novel form of lattice for atoms. This lattice does not arise from a spatially varying light intensity pattern, as is the case for traditional optical lattices.  Instead, laser radiation generates an effective magnetic field that changes the... Read more

An optical switch developed at the Joint Quantum Institute (JQI) spurs the prospective integration of photonics and electronics. The JQI switch can steer a beam of light from one direction to another in only 120 ps using only about 90 attojoules of input power. At the wavelength used, in the... Read more

New PFC-supported work shows how a simple “joystick” consisting of an adjustable magnetic field can create several new phases of atomtronic matter, many of them never seen before. The field is used to tune the interaction---giving the researcher force on demand, causing the atoms to assume... Read more

PFC research at the Joint Quantum Institute (JQI) has for the first time engineered and detected the presence of effective high angular momentum collisions between atoms at temperatures close to absolute zero. Previous experiments with ultracold atoms featured essentially head-on collisions. The... Read more

Electrons carry information over tiny distances in computer circuitry. Photons are commonly used to carry information over kilometer distances. Scientists are currently developing micron-scale optical devices to replace and/or be compatible with electron-based circuit elements.

Diodes... Read more

Ultracold atomic gases trapped by laser light have become a playground for exploring quantum matter and even uncovering new phenomena not yet seen in nature.

PFC researchers at JQI have shown that this kind of optical lattice system can exhibit a never-before-seen quantum state called a... Read more

If quantum computers are ever to be realized, they likely will be made of different components sharing information with one another, just as the memory and logic circuits in today's computers do. Yet, it remains unclear how the quantum states in these different systems interact.

A team of... Read more

PFC-supported research at JQI has uncovered evidence for a long-sought-after quantum state of matter, a spin liquid. You can’t pour a spin liquid into a glass.  It’s not a material at all, at least not a material you can touch. It is more like a kind of magnetic disorder within an ordered array... Read more

Quantum spin models are powerful because they can describe many types of physical phenomena such as phase transitions in magnets. Simulations of these models can provide insights when the actual system of interest is difficult to understand theoretically or challenging to experimentally probe.... Read more

Researchers in a collaboration between the PFC at JQI and CalTech have shown that it may be possible to take a conventional semiconductor and endow it with topological properties without subjecting the material to extreme environmental conditions or fundamentally changing its solid state... Read more

In atomtronics scientists construct circuit elements using ultra-cold atomic gases where the atoms take the role of electrons. PFC scientists have developed an experiment that not only generates... Read more

PFC experimentalists in the Trapped Ion Quantum Information group have performed a gate that flips the state of a single atomic qubit in less than 50 picoseconds. The time to perform this same operation with continuous wave (CW) ... Read more

PFC-supported researchers, lead by Ian Spielman, recently demonstrated for the first time spin-orbit coupling in Bose-Einstein condensates (BECs), where the neutral atoms exhibited properties similar to electrons in material systems.

The scientists engineered a laser-atom interaction... Read more

“Frustrated" ensembles of interacting components – that is, those which cannot settle into a state that minimizes each interaction – may be the key to understanding a host of puzzling phenomena that affect systems from neural networks and social structures to protein folding and magnetism.... Read more

Random number sequences are needed for data encryption and other critical uses – yet truly random numbers are nearly impossible to come by. All classical processes such as coin flips are, in principle, predictable. But one thing that absolutely cannot be predicted is the value resulting... Read more

For the first time, scientists have employed a powerful technique of laser physics – the “optical frequency comb” – to entangle two trapped atoms. This form of control is a promising candidate for use as a logic gate for quantum computing and information-processing, and offers substantial... Read more

PFC-supported scientists have devised a new method that could be used to generate multiple pairs of “indistinguishable” photons – near-identical individual quanta of light – by fine-tuning the output from two separate quantum dots. Manipulating single photons will play a role in any eventual... Read more

Topological quantum computing (TQC), in which the data are protected against decoherence because they are stored and manipulated as shapes, is a highly desirable goal in quantum information science. Unfortunately, the only physical system in which anything approaching topological protection has... Read more

Physicists supported by the PFC at the Joint Quantum Institute have developed a new source of “entangled” photons – fundamental units of light whose properties are so intertwined that if the condition of one is measured, the condition of the other is instantaneously known, even if the photons... Read more

The behavior of quantum dots – nanometer-scale semiconductor formations that have many of the same quantized properties as atoms when interacting with light – is a subject of intense interest in condensed-matter physics. Now researchers supported by the Joint Quantum Institute’s Physics Frontier... Read more

PFC-supported scientists have demonstrated a new way to control quantum interactions that makes it possible to fine-tune the way in which the spin properties of trapped atoms couple to, and are "entangled" with, those of their neighbors -- a development with potentially important applications in... Read more

Quantum entanglement, a condition in which the states of two different objects become so inextricably linked that neither can be described separately, is an essential element of any future quantum computer. Scientists have succeeded in entangling many sorts of entities, typically identical atom... Read more

The simplest form of Bose-Einstein condensation occurs when a number of bosonic atoms (those with integer net spin) coalesce into the lowest possible energy state. Such condensates exhibit macrosopic quantum interference, persistent vortex currents and other manifestations of superfluidity. ... Read more

 

PFC-supported physicists have created and demonstrated a remote “quantum gate” – a key component for long-range quantum information transfer and an essential... Read more

Ian Spielman of the Joint Quantum Institute proposed a novel experimental protocol whereby neutral atoms in a Bose-Einstein condensate would behave like charged particles in a magnetic field. Physicists can use such an arrangement to create precisely tunable models to study the dynamics of... Read more

Twenty years ago, Purdue University scientists proposed a highly promising design for a “spin effect” transistor – the Datta-Das transistor, or DDT. To date, however, no one has been able to build a working model. Now JQI researchers have devised a potential solution to the problem: creating a... Read more

Neutral atoms, having no net electric charge, usually don't act very dramatically around a magnetic field. But by “dressing up” a Bose-Einstein condensate of rubidium atoms – applying two beams of laser light, thus giving the atoms an effective directional tendency, or vector potential -- PFC... Read more

Topological insulators form in certain materials that, in bulk, have the distinctive physical signature of insulators: That is, the permitted energy levels (or “bands”) in their component atomic structures are characterized by a full valence band and an empty conduction band, with a substantial... Read more

Two ions are placed in separate, unconnected traps 1 meter apart. A “message” is imprinted on Ion A via a microwave pulse. Then the ions are excited into a state in which they emit one photon each. Either photon can be one of two slightly different wavelengths. Those photons travel through... Read more

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About the PFC @ JQI

The Physics Frontier Center is devoted to leading-edge experimental and theoretical investigation of ways to control and process quantum coherence and entanglement: the physics of quantum information. It is funded through a cooperative agreement with the National Science Foundation (NSF) and operated within the Joint Quantum Institute (JQI), a partnership between the University of Maryland (UMD) and the National Institute of Standards and Technology (NIST), with additional support from the Laboratory for Physical Sciences.

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PFC and JQI researchers engage the public in quantum research. Click here to request a visit from one of our scientists!

PFC General Info: pfc-info@umd.edu   Academic and Research Info: Luis Orozco | Atlantic Building 2203 | (301) 405-9740 | lorozco@umd.edu