Items tagged with "quantum computing"
NSF has announced a $15 million award to a collaboration of seven institutions including the University of Maryland. The goal: Build the world’s first practical quantum computer.
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.
Two independent teams of scientists, including one from the Joint Quantum Institute, have used more than 50 interacting atomic qubits to mimic magnetic quantum matter, blowing past the complexity of previous demonstrations. The results appear in this week’s issue of Nature.
Large-scale quantum computers, which are an active pursuit of many university labs and tech giants, remain years away. But that hasn’t stopped some scientists from thinking ahead, to a time when quantum computers might be linked together in a network or a single quantum computer might be split up across many interconnected nodes.
Deep within solids, individual electrons zip around on a nanoscale highway paved with atoms. For the most part, these electrons avoid one another, kept in separate lanes by their mutual repulsion. But vibrations in the atomic road can blur their lanes and sometimes allow the tiny particles to pair up. The result is smooth and lossless travel, and it’s one way to create superconductivity.
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 different technologies.
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 implementing a proposed type of gate, which does not rely on super-cooling their ion qubits.
A team of researchers led by Duke University and the University of Maryland has been tapped by the nation’s “Q Branch” to take quantum computing efforts to the next level using one of the field’s leading technologies—ion traps.
Symmetry permeates nature, from the radial symmetry of flowers to the left-right symmetry of the human body. As such, it provides a natural way of classifying objects by grouping those that share the same symmetry. This is particularly useful for describing transitions between phases of matter. For example, liquid and gas phases have translational symmetry, meaning the arrangement of molecules doesn’t change regardless of the direction from which they are observed.
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.