IBM leads the world again with 433 quantum bits!
At IBM's annual Quantum Summit on November 9, 2022, IBM unveiled the Osprey chip, which has about three times more than Eagle (127 quantum bits) with 433 quantum bits [1].IBM said that progress in tripling the number of quantum bits on the chip in just one year indicates that the company is on track to deliver the world's first computer in 2023 with more than 1,000 quantum bits in Condor, the world's first general-purpose quantum computer.
Relative sizes of successive generations of IBM quantum processors. in 2016, the company put the first quantum computer on the cloud for everyone to experiment with - a device with five quantum bits, each superconducting circuit cooled to about 20 milliKelvin (-273 degrees C). in 2019, IBM introduced the 27-quantum-bit Falcon; in 2020, the 65-quantum-bit Hummingbird; and in 2021, the 127-quantum-bit Eagle.
01Say goodbye to "chandelier", Osprey all-round upgrade
An exploded view of the Osprey processor, showing the 3D package.
At the IBM Quantum Summit 2022, IBM shared more than 10 announcements and showcased new quantum computing hardware, software capabilities to extract value from these processors, and how products and services can help create a global quantum computing ecosystem.
The first IBM announcement at the summit announced the launch of the 433-quantum-bit IBM Quantum Osprey - the largest general-purpose quantum processor to date. It is three times larger than Eagle, IBM Quantum's 100-quantum-bit breakthrough processor. Like Eagle, Osprey includes multi-level wiring to provide flexibility in signal routing and device layout, as well as integrated filtering to reduce noise and improve stability.
One strategy that began with Eagle and carried over to Osprey was to separate the wires and other components needed for readout and control to their own layer. This multi-level wiring helps protect vulnerable quantum bits from damage and helps processors integrate larger numbers of quantum bits.
Oliver Dial, chief hardware architect at IBM Quantum, said [2], "We may not need all these technologies to deploy 100 quantum bits, but everything done helps build Osprey and Condor (the 1121-qubit Condor general-purpose quantum processor expected in 2023 ), we now have the technology to go beyond 100 quantum bits."
Dial noted that beyond the chip, Osprey has two major advantages over Eagle.
Previous-generation coaxial cabling (left) and new Cryoflex cabling (right). No more "quantum chandeliers": IBM says its Osprey processors introduce high-density control signaling using flexible cabling.
One is a "quantum chandelier" that replaces the microwave cables IBM used with its previous quantum processors with flexible ribbon cables, "which you might find if you turn on your phone or laptop to carry signals between the motherboard and the screen. All of these microwave cables that pass microwave signals in and out of the coolers that store quantum bits are not very scalable," Dial said.
Osprey's flexible ribbon cables are suitable for low-temperature environments. The cables' resistance and thermal resistance are specifically designed to help microwave signals flow without conducting too much heat that could interfere with the quantum bits, Dial explained, which resulted in a 77 percent increase in the number of connections to the chip. "Basically, there are almost twice as many wires" - something that will help IBM scale up its quantum computers.
Another major advantage of Osprey is a new generation of control electronics that can send and receive microwave signals to and from the quantum processor. While Dial says IBM's Phase 1 control electronics (2019-2021) enjoy greater flexibility, Osprey's control electronics are "more specialized and better suited to quantum devices to produce the precise signals, frequencies, and power needs we need.
These improvements "reduce cost, which is an important consideration as we scale up," Dial said. "For our first generation of 5- and 20-qubit devices, we needed a full rack of control electronics, and with Eagle, we're seeing 40 quantum bits per rack. Now we can control more than 400 quantum bits with a single rack of devices." Osprey has also increased its quantum bit density, he added.
Osprey's new control electronics include a low-temperature CMOS controller chip that is implemented using 14nm FinFET technology and operates at about 4 Kelvin (-269.15 degrees Celsius). It uses an application-specific integrated circuit (ASIC) design that is smaller in size and power consumption than previous field-programmable gate array (FPGA) approaches. "Unlike our previous need of about 100 watts per quantum bit, we only need about 10 milliwatts, so we can fit more quantum bits on the chip," Dial said.
IBM's focus in this advance is on introducing the key technologies needed to scale the number of quantum bits. However, many elements of the quantum bit architecture are similar to those used in the Eagle (ibm_washington) device, which will continue to use IBM's Quantum System One package introduced in 2019.
Osprey will be available to members of the IBM Quantum Network in the first quarter of 2023. The current version of the device, R1, has many quantum bit quality metrics similar to previous generations, with T1 coherence times in the 70-100 microsecond range.
The next version of Osprey, called R2, will make several improvements in coherence time that were first tested on one of the 27 quantum bit Falcon devices and improve this coherence by a factor of 2-3. Improving these will be the focus of the next generation of Heron processors that IBM plans to launch in 2023.
02 2023, the next wave of quantum computing
IBM has been developing industry-leading hardware, software and services for users to be ready for the next wave of computing, and in 2022, will no longer just be ready as we continue to deliver on our development roadmap," IBM said. We are ready to start enabling the next wave of computing and with it, useful quantum computing."
"2023 will be an important inflection point: we are ready to start enabling quantum-centric supercomputers. This is a modular computing architecture that enables scaling and combines quantum communication and computation to increase computational power, while employing hybrid cloud middleware to seamlessly integrate quantum and classical workflows."
03More breakthroughs: new quantum volumes, CLOPS measures, error mitigation ......
In addition, IBM unveiled more other breakthroughs at the annual Two Word Summit.
1) New Quantum Volume and CLOPS Metrics Achieved
IBM used their 27 quantum bit Falcon device to test, improve and has now achieved a quantum volume metric of 512 and a CLOPS measure of 15.7K. The CLOPS improvements are significant as they started the year at 1.4K and showed a 10x improvement this year.
Dial said IBM's best system has increased from 1,400 CLOPS to 15,000 CLOPS based on the IBM quantum computing speed metric known as Circuit Level Operations Per Second (CLOPS). (Quantum programmers run quantum algorithms on quantum computers consisting of quantum circuits that describe the basic sequence of operations applied to a set of quantum bits) -- quantum gates; CLOPS is a measure of the speed at which a quantum computer runs quantum circuits.)
2) Error suppression and mitigation techniques
IBM is also preparing to include optional error mitigation techniques in its cloud software for quantum computers, which essentially trade speed for more accurate results. Error suppression uses a technique called dynamic decoupling, which modulates control pulses in a way that reduces decoherence and crosstalk. Error mitigation uses a variety of different algorithms to provide more accurate answers using different techniques. two of the algorithms used by IBM are called zero-noise extrapolation and probabilistic error elimination.
The tradeoff for using these algorithms is that they can significantly increase the overall run time of a job, as they may require multiple iterations to provide an answer. As a result, users are forced to make a trade-off between accuracy and run time. To make it easier for end users, IBM is implementing a simple control that allows end users to specify how much relief they want and then let the software implement it automatically. The control, called resiliency level, can be set anywhere from level0 (no mitigation algorithm) to level3 (maximum mitigation algorithm), with level1 and 2 falling somewhere in between.
"Instead of pushing complexity onto the user, we're building these features on the back end to handle these details," Dial said. "By the end of 2024, we expect to be able to do this by running multiple Heron chips in parallel in our '100 x 100 program' running multiple Heron chips in parallel to mitigate errors, allowing for systems 100 quantum bits wide and 100 gates deep to achieve capabilities beyond classical computers."
3) Dynamic Circuits
IBM also disclosed their offering of dynamic circuitry (sometimes called intermediate circuitry measurement): it is now available on 18 systems. This feature allows end users to measure quantum bits and branch in their code based on the measurements. The measured quantum bits can then be reset and reused later in the program. This capability can reduce the circuit depth and/or reduce the number of quantum bits required to implement the algorithm.
While we have not had many user programs take advantage of this capability, it is still fairly new. It is expected that this capability will become more important as error correction techniques are implemented to detect and subsequently correct quantum bit errors.
4) Circuit Weaving and Quantum Serverless
IBM also announced that it has released alpha versions of two features. Circuit weaving entails splitting large quantum programs into separate parts that can run independently. The output of the runs can then be fed into a classical computer and then combined to provide answers. This approach may allow users to run programs larger than one machine, or allow programs to run faster if the separate parts can be run in parallel on multiple quantum processors.
5) New packaging for IBM Quantum System 2
The new packaging of IBM Quantum System 2 is designed with modularity in mind for better scalability and a vision of entering the era of quantum dominance. The design will accommodate a variety of different configurations and ways to facilitate networking by having multiple systems placed physically close together [3].
Possible IBM Quantum System 2 configuration with 1 (left), 2 (center) and 3 (right) cryostats
In the figure above, the cryostats (C1, C2 and C3) are hexagonal and the control electronics are placed in the wings connected to the cryostats. The wings are flexible and scalable to accommodate the electronics needed for different numbers of quantum bits. And as shown in the middle and right images, the cryostats can be placed together to minimize the communication distance between quantum bits in different cryostats. Using the Kookaburra chip, each cryostat can hold 4,158 quantum bits, so a device with three of them can hold 12,474 or more quantum bits.
The IBM Quantum System 2 package is scheduled to launch at the end of 2023: the culmination of IBM's move toward quantum computer construction, representing a step toward the quantum era.
Not only the aforementioned technological breakthroughs, IBM also announced that it is working with communications technology company Vodafone to develop post-quantum cryptography that could defend against future quantum computers that could quickly disrupt modern cryptography. "We are looking at cryptographic flexibility, the ability to move between cryptographic schemes to confirm how encryption is constantly changing and progressing."
04Some thoughts and suggestions
Predictably, there are only three voices in China after IBM launched the 433 quantum bit chip.
One is that IBM is too powerful, China doesn't even have 100 bits, it's really garbage; another is that IBM is too powerful, China must cheer up; the last one is, see, quantum computing is too awesome, come and vote for our company!
The view of photon box is, of course, to face the gap between our superconducting quantum computer and IBM, but there is no need to have negative emotions, to believe in the layout of the country and the efforts of scientists. On the other hand, other quantum computing companies that take advantage of the IBM hype, it is not necessary, IBM cattle does not mean that you also cattle, first you come up with results.
It can be seen that the gap with IBM is not only the gap of quantum bits, but a full range of gaps from refrigeration, electronic control equipment to wiring. Finally, we call, quantum computer is not just a matter of scientific researchers, but also needs the full range of support from other links, from dilute refrigeration machine, quantum measurement and control system to coaxial cable are in urgent need of a breakthrough, we hope that all walks of life join together to promote the progress of China's quantum computer.
Reference links：
[1]https://research.ibm.com/blog/next-wave-quantum-centric-supercomputing
[2]https://spectrum.ieee.org/ibm-quantum-computer-osprey
[3]https://quantumcomputingreport.com/ibm-announces-433-qubit-osprey-processor-several-additional-advancements-and-a-100x100-challenge/
