Physics Frontier Center

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

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

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

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

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

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 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

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

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

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

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