IBM about to break the 1000 quantum bit mark
IBM's Condor, the world's first general-purpose quantum computer with more than 1,000 quantum bits, is about to break the 1,000-quantum-bit mark!
Also expected in 2023, IBM will introduce Heron: IBM's first modular quantum processors, which IBM says will help it produce quantum computers with more than 4,000 quantum bits by 2025.
A researcher at IBM's Thomas J. Watson Research Center examines quantum hardware
01Organized and on the verge of 1,000 quantum bits
While quantum computers could theoretically quickly find answers to problems that take years to solve with classical computers, today's quantum hardware still lacks quantum bits, limiting its usefulness. The entanglement and other quantum states required for quantum computing are notoriously fragile and susceptible to heat and other disturbances, making scaling up the number of quantum bits a huge technical challenge.
Nevertheless, IBM has steadily increased the number of its quantum bits. in 2016, it put the first quantum computer in the cloud [1]: a device with five quantum bits, each a superconducting circuit cooled to near absolute zero. in 2019, IBM created the 27-quantum-bit Falcon; in 2020, the 65-quantum-bit Hummingbird; in 2021, the 127-quantum-bit Eagle, the first quantum processor with more than 100 quantum bits; and in 2022, the 433-quantum-bit Osprey.
IBM expects to build increasingly complex quantum computers in the next few years, starting with computers using Condor processors or multiple Heron processors in parallel.
02More than the number of quantum bits for a breakthrough
Other quantum computers have more quantum bits than IBM's 1121-quantum-bit Condor processor. For example, D-Wave Systems announced a 5,000-quantum-bit system in 2020 [2]. But while D-Wave's computers are specialized machines that solve optimization problems, Condor will be the world's largest general-purpose quantum processor.
1,000 quantum bits really pushes the envelope of what we can really integrate," said Jerry Chow, IBM's director of quantum infrastructure. By separating the wires and other components needed for readout and control onto their own layer, a strategy that began with Eagle, the researchers say they can better protect the quantum bits from damage and increase their number."
IBM's other quantum processor, Heron, planned for 2023, has only 133 quantum bits, which is not large compared to Condor. But IBM says its upgraded architecture and modular design herald a new strategy for developing powerful quantum computers. while Condor uses a fixed-coupling architecture to connect its quantum bits, Heron will use a tunable coupling architecture that adds Josephson junctions between the superconducting rings that carry the quantum bits. This strategy reduces crosstalk between quantum bits, increasing processing speed and reducing errors. However, Google has already used this architecture in its 53-bit Sycamore processor.
In addition, Heron processors are designed to communicate with each other classically in real time. The classical nature of these links means that their quantum bits cannot be entangled between Heron chips to achieve the kind of computational power gains that quantum processors are known for. However, these classical links enable "circuit weaving" techniques [3], where quantum computers can get help from classical computers.
For example, using a technique called "entanglement forging" [4], IBM researchers found that they could simulate quantum systems such as molecules, using only half the quantum bits normally required. This approach divides a quantum system into two halves, models each half on a quantum computer, and then uses classical computing to calculate the entanglement between the two halves and weave the models together.
While these classical techniques between processors are helpful, IBM intends to eventually replace them. in 2024, IBM aims to launch Crossbill, a 408-quantum-bit processor made of three microchips coupled via a short-range quantum communication link, and Flamingo, a 462-quantum-bit module, which is planned to be coupled via a roughly 1-meter-long quantum communication link to unite into a 1386-quantum-bit system. If these connectivity experiments are successful, IBM aims to announce its 1386-bit Kookaburra module in 2025, combining three such modules into a 4158-bit system using short-range and long-range quantum communication links.
IBM Quantum Development Roadmap to 2022
Franco Nori, chief scientist at RIKEN's Laboratory for Theoretical Quantum Physics in Japan, commented, "IBM's methodical strategy will lead to success in the long run."
03In addition to hardware, software will also make leaps and bounds
In 2023, IBM also plans to improve its core software to help developers through the cloud in order to unify the use of quantum and classical computing. "We're laying the groundwork for what a quantum-centric supercomputer would look like, and we don't see quantum processors as fully integrated, but loosely aggregated." Chow explained that this framework will provide the flexibility necessary to accommodate the constant upgrades that quantum hardware and software are likely to experience.
In 2023, IBM plans to begin developing prototype quantum software applications; by 2025, the company expects to introduce such applications in machine learning, optimization problems, natural sciences and other areas.
The researchers hope to eventually use quantum error correction to compensate for the error-prone nature of quantum processors. These schemes spread quantum data over redundant quantum bits, with multiple physical quantum bits required for each useful logical quantum bit. Instead, IBM plans to include error mitigation schemes on its platform starting in 2024 [5] to prevent these errors in the first place. However, even if more quantum bits are eventually needed to handle errors, IBM should be in a good position with its 1121 quantum bits of Condor, for example.
Reference link：
[1]https://spectrum.ieee.org/ibm-puts-a-quantum-processor-in-the-cloud
[2]https://www.dwavesys.com/company/newsroom/press-release/d-wave-announces-general-availability-of-first-quantum-computer-built-for-business/
[3]https://research.ibm.com/blog/circuit-knitting-with-classical-communication
[4]https://spectrum.ieee.org/ibm-entanglement-forging[5]https://spectrum.ieee.org/quantum-error-correction
