A novel mechanism of inflation is proposed where, starting only from a preexisting de Sitter background, no scalar fields are present, and density perturbations arise from the nonlinear evolution of gravitational waves, which unavoidably arise as quantum vacuum oscillations of the metric. This model-free picture of the early Universe gives concrete predictions that can be tested against cosmological observations.
First time quantum light sources, control electronics are tightly integrated on a silicon chip.
A packaged circuit board containing the chip placed under microscope in probe station during an experiment. The first-of-its-kind silicon chip combines both the quantum light-generating components (photonics) with classical electronic control circuits — all packed into an area measuring just one millimeter by one millimeter.
Two independent groups optimize diamond-based quantum sensing by using more than 100 such sensors in parallel.
Diamond has long been prized for its beauty, and it holds the record as the hardest known natural material. By introducing nitrogen atoms into its crystal lattice, it can also be transformed into a remarkable quantum sensor. The associated crystal defects are known as nitrogen-vacancy (NV) centers, and they imbue such sensors with unprecedented electromagnetic-field sensitivity and excellent spatial resolution [1]. However, experimental platforms designed to exploit these sensors have so far had limited applicability because the sensing speed and resolution are difficult to simultaneously optimize. Now two research teams—one led by Shimon Kolkowitz at the University of California, Berkeley, [2] and the other by Nathalie de Leon at Princeton University [3]—have independently developed a way of manipulating and measuring more than 100 NV centers in parallel (Fig. 1).
Quantum networking is being rapidly developed world-wide. It is a key quantum technology that will enable a global quantum internet: the ability to deploy secure communication at scale, and to connect quantum computers globally. The race to realize this vision is in full swing, both on Earth and in space.
New research, in collaboration between Igor Pikovski at Stevens Institute of Technology, Jacob Covey at the University of Illinois at Urbana-Champaign and Johannes Borregaard at Harvard University, suggests that quantum networks are more versatile than previously thought.
In the paper titled “Probing Curved Spacetime with a Distributed Atomic Processor Clock”, published in the journal PRX Quantum, the researchers show that this technology can probe how curved space-time affects quantum theory —a first test of this kind.
The quantum computing revolution draws ever nearer, but the need for a computer that makes correctable errors continues to hold it back.
Through a collaboration with IBM led by Cornell, researchers have brought that revolution one step closer, achieving two major breakthroughs. First, they demonstrated an error-resistant implementation of universal quantum gates, the essential building blocks of quantum computation. Second, they showcased the power of a topological quantum computer in solving hard problems that a conventional computer couldn’t manage.
In the article “Realizing String-Net Condensation: Fibonacci Anyon Braiding for Universal Gates and Sampling Chromatic Polynomials” published in Nature Communications, an international collaboration between researchers at IBM, Cornell, Harvard University and the Weizman Institute of Science demonstrated, for the first time, the ability to encode information by braiding—moving in a particular order—Fibonacci string net condensate (Fib SNC) anyons, which are exotic quasi-particles, in two dimensional space.
Can you prove whether a large quantum system truly behaves according to the weird and wonderful rules of quantum mechanics—or if it just looks like it does? In a new study, physicists from Leiden, Beijing and Hangzhou found the answer to this question.
You could call it a “quantum lie detector”: Bell’s test designed by famous physicist John Bell. This test shows whether a machine, like a quantum computer, is truly using quantum effects or just mimics them.
As quantum technologies become more mature, ever more stringent tests of quantumness become necessary. In this new study, the researchers took things to the next level, testing Bell correlations in systems with up to 73 qubits—the basic building blocks of a quantum computer.
Macquarie University researchers have demonstrated a technique to dramatically narrow the linewidth of a laser beam by a factor of over ten thousand—a discovery that could revolutionize quantum computing, atomic clocks and gravitational wave detection.
In research published in APL Photonics, the team described using diamond crystals and the Raman effect—where laser light stimulates vibrations in materials and then scatters off those vibrations—to narrow the linewidth of laser beams by factors exceeding 10,000.
Laser linewidth measures how precisely a beam of light maintains its frequency and color purity. The narrower the linewidth, the more monochromatic and spectrally pure the laser. The team’s theoretical predictions suggest even greater improvements are possible with the method they have developed.
