A cryogenic optical cavity for trapped Yb+ quantum networking

Abstract: One approach to ion-photon entanglement relies on transitions from 2P3/2 to the low-lying 2D3/2 and 2D5/2 states at 1345 nm and 1650 nm in Yb+ [1]. Here Purcell enhancement is crucial for achieving good performance in the context of quantum networking. In support of this effort, we developed a monolithic, fiber-coupled Fabry–Pérot cavity integrated with a blade trap that operates at cryogenic temperatures. One of the cavity mirrors is bonded to a metalens that mode-matches cavity light to a single-mode fiber.

Anyone for Anyons?

Researchers have demonstrated that a strange type of quantum particle called the anyon, believed to exist in only two dimensions, can also be created in one dimension. Further studies exploring different types of one-dimensional anyons could bring scientists one step closer to using the particles as a fundamental unit of memory in a quantum computer.

The Rayleigh-Taylor instability in a binary quantum fluid

Abstract: Instabilities, where initially small fluctuations seed the formation of large-scale structures, govern the dynamics in various fluid flows. The Rayleigh-Taylor instability (RTI) is an iconic example that leads to the development of mushroom-shaped incursions when immiscible fluids are accelerated into each other. RTI drives structure formation throughout science and engineering including table-top oil and water mixtures; supernova explosions; and inertial confinement fusion.  Despite its ubiquity, controlled laboratory RTI experiments are technically challenging.

International Year of Quantum Science and Technology

To mark a century of progress in quantum science, the United Nations General Assembly has declared 2025 to be the International Year of Quantum Science and Technology (IYQ). To celebrate the occasion, governments, professional societies, academic institutions and many others will be sharing the story of quantum science—its past, present and future—with audiences around the world.

JQI is excited to join in the fun, and we will share our events and initiatives here and on our social media channels. Some notable events are:

A Constructive Approach to Zauner’s Conjecture via the Stark Conjectures

Abstract: In this talk, I will present a construction of symmetric informationally complete POVMs (SIC-POVMs), a special class of quantum measurements whose existence in all dimensions was conjectured by Zauner in 1999. Equivalently, these are maximal sets of d^2 equiangular lines in ℂ^d. Our approach introduces an explicit mathematical object, the ghost SIC, built from number-theoretic properties of a special modular function, and we show that it is Galois conjugateto an actual SIC.