QuEra Stealth Quantum Computer Startup Reveals 256 Qubit Simulator

QuEra Computing Inc. emerged from stealth mode has revealed a completed 256 qubit device. QuEra Computing Inc. emerged from stealth mode today with $17 million in funding from Rakuten, Day One Ventures, Frontiers Capital and leading tech investors Serguei Beloussov, and Paul Maritz among others. The company recently received a DARPA award, and has already generated $11 million in revenue. QuEra Computing uses ground-breaking research on neutral atoms, developed at Harvard University and the Massachusetts Institute of Technology, as the basis for a world-leading scalable, programmable quantum computer solution. The QuEra team is building the world’s most powerful quantum computers to take on computational tasks that are currently deemed impossibly hard.

QuEra’s quantum machines utilize nature’s perfect qubits based on Rydberg atoms — fast, high-quality gates, and scalability to millions of qubits.

Development machines (256-512 qubit) with full-stack software allowing quantum simulation and prototyping various algorithms accessible by the end of 2021.

Scientific applications: quantum advantage in characterizing new phases of matter that are impossible to analyze with conventional computers; computer science research.

Scientific applications: predicting new phases of matter, computer science research, simulating physical models of materials.

Specialized applications: Integrating quantum simulators with machine learning algorithms.

Widespread use: optimization (for logistics, scheduling, finance).

Specialized applications: Sampling probability distributions.

Scientific applications: predicting new phases of matter, computer science research, simulating physical models of materials, scientific discoveries in various fields (condensed matter physics, high-energy physics, gravity, biophysics, chemistry).

Specialized applications: machine learning,

Widespread use: optimization for logistics, scheduling, finance; chemistry and material simulation (better batteries, better catalysts).

Nature’s perfect qubits
Atoms are nature’s perfect qubits, all identical to one another without even the possibility of defects. They leverage these properties to store and process quantum information.

Using our advanced techniques of atom-by-atom assembly, it is possible to arrange Rydberg atoms in a large 1D, 2D, or 3D array and be addressed individually with high precision, promising very high scalability.

High-quality multi-qubit gates
Rydberg atoms interact on-demand – when illuminated with laser light, they take on enormous size and interact over long distances, but left in the dark, they keep to themselves.

Entering a nonsimulatable regime
The QuEra machine is entering a nonsimulatable regime for practical problems, such as scientific simulation and optimization. In such regimes, classical supercomputers are not adequate for solving problems.

Efficient error correction
QuEra systems allow for creating states of qubits that are protected from errors. This increases the computational power of QuEra machines significantly.

Hardware-efficient implementation of multi-qubit gates
Using long-ranged interactions between atomic qubits, our machine can efficiently implement multi-qubit gates. Reducing the overhead in decomposing multi-qubit gates into a sequence of singe-qubit and two-qubit operations increases the quality of the results. This provides an opportunity for a new class of algorithms.

Nature – Quantum phases of matter on a 256-atom programmable quantum simulator

Arxiv – Hardware-Efficient, Fault-Tolerant Quantum Computation with Rydberg Atoms

The QuEra Approach

The QuEra hardware uses arrays of neutral atoms where hundreds of atoms are cooled and then arranged by laser fields in a small vacuum chamber. While the chamber’s glass walls are at room temperature, just millimeters away the atoms are laser-cooled to a virtual standstill, reaching one millionth of a degree Kelvin above absolute zero. That is over a million times colder than deep space and over a thousand times colder than the superconducting qubits by other industry participants like IBM and Google. Unlike quantum computers based on trapped ions, which repel in close-packed quarters, QuEra’s system can arrange hundreds of neutral atoms into sub-millimeter arrays. By way of comparison to classical computing, this density is similar to the transistor density on a late 1990s Intel CPU. However, instead of connecting transistors by wires, QuEra connects its neutral-atom qubits by “Rydberg blockade.” In Rydberg blockade, laser flashes drive electrons in selected atoms to an outer orbital which causes the parent atoms to briefly “puff up” – but only on the condition that it is not blocked by another puffed up atom. This blockade forms QuEra’s conditional logic gate and can happen in as short of a time period as a few nanoseconds, once again similar to a 1990s Intel CPU. However, unlike a conventional CPU, the computational power of a quantum computer is exponential in the number of qubits. QuEra has completed the construction of their first 256-qubit device which will be soon accessible to customers. This device holds the promise to prove useful today – not years from now – by targeting applications in quantum optimization and quantum simulation. This is QuEra’s first step towards addressing today’s “impossible problems” in materials, finance, chemistry, logistics, pharmaceuticals and more. “There is an enormous opportunity to make headway on some of today’s most critical –and presently impossible – problems that impact nearly every one of us,” said Alex Keesling, CEO of QuEra and co-inventor of QuEra’s technology. “With our first machine, we are excited to begin to demonstrate what quantum computers can do for humanity.” “QuEra’s proprietary technology combined with its team of pioneers in quantum computing is unmatched,” said Takuya Kitagawa, Chief Data Officer at Rakuten, who led Rakuten’s investment in QuEra. “QuEra will accelerate the quantum computing industry’s trajectory, making it a technology not of the future, but of today.” The QuEra team is taking a stepwise approach where it will continue to boost the technology’s power while closing in on “universal quantum computers” with thousands of logical qubits.

Nature Abstract
Motivated by far-reaching applications ranging from quantum simulations of complex processes in physics and chemistry to quantum information processing1, a broad effort is currently underway to build large-scale programmable quantum systems. Such systems provide insights into strongly correlated quantum matter while at the same time enabling new methods for computation and metrology. Here we demonstrate a programmable quantum simulator based on deterministically prepared two-dimensional arrays of neutral atoms, featuring strong interactions controlled by coherent atomic excitation into Rydberg states. Using this approach, we realize a quantum spin model with tunable interactions for system sizes ranging from 64 to 256 qubits. We benchmark the system by characterizing high-fidelity antiferromagnetically ordered states and demonstrating quantum critical dynamics consistent with an Ising quantum phase transition in (2 + 1) dimensions. We then create and study several new quantum phases that arise from the interplay between interactions and coherent laser excitation, experimentally map the phase diagram and investigate the role of quantum fluctuations. Offering a new lens into the study of complex quantum matter, these observations pave the way for investigations of exotic quantum phases, non-equilibrium entanglement dynamics and hardware-efficient realization of quantum algorithms.

Arxiv Abstract

Neutral atom arrays have recently emerged as a promising platform for quantum information processing. One important remaining roadblock for large-scale quantum information processing in such systems is associated with the finite lifetime of atomic Rydberg states during entangling operations. Because such Rydberg state decay errors can result in many possible channels of leakage out of the computational subspace as well as correlated errors, they cannot be addressed directly through traditional methods of fault-tolerant quantum computation. Here, we present a detailed analysis of the effects of these sources of errors on a neutral-atom quantum computer and propose hardware-efficient, fault-tolerant quantum computation schemes that mitigate them. By using the specific structure of the error model, the multi-level nature of atoms, and dipole selection rules, we find that the resource cost for fault-tolerant quantum computation can be significantly reduced compared to existing, general-purpose schemes, even when these novel types of errors are accounted for. We illustrate the experimental feasibility of our protocols through concrete examples with qubits encoded in 87Rb, 85Rb, or 87Sr atoms. Finally, implications for both the near-term and scalable implementations are discussed.

SOURCES- QuEra, Nature, Arxiv
Written by Brian Wang, Nextbigfuture.com