Introduction
IBM made a historic declaration at its annual Quantum Summit that it had designed a quantum computer chip sustaining 1,000 qubits at low error rates that allow executing meaningful algorithms. The breakthrough that experts have considered as the rough threshold for ‘quantum advantage’ puts IBM at the front in a competition in the technology race with the application in every computationally intensive field.
It will become clear later why a quantum computer with 1,000 qubits represents such a breakthrough. First of all, one should understand what a qubit is and how challenging the process of reaching this point is. In contrast to a conventional bit, a qubit is a quantum information carrier. It has to sustain a quantum state, being processed and manipulated by the quantum algorithms.
Scaling the qubit number from dozens to hundreds and then to thousands involves overcoming numerous technological issues related to physics, materials, cryogenics, and microwave engineering.
Years of engineering innovations in all these areas resulted in the emergence of IBM’s latest product, the Heron R2 processor that many experts consider as the most outstanding advance in the field since the 2019 Google’s ‘quantum supremacy’ experiment.
Why 1,000 Qubits Matter
One can think of a quantum computer as a conventional classical computer with an important difference. Classical computers employ bits as information carriers – the pieces of information can be either 0 or 1. A quantum bit (qubit) exists in a superposition state – it can take both 0 and 1 values at once.
Moreover, entangled qubits coordinate the states with one another, making certain types of computations run exponentially faster than conventional classical approaches allow. Therefore, quantum computers represent an advanced technology capable of providing unprecedentedly fast computations.
However, qubits represent a rather fragile construct and may experience ‘decoherence’ under the influence of thermal noise and electromagnetic interference. To ensure fault-tolerant operations, scientists have developed the surface code error correction protocol to reduce logical error rates below 0.1%, which is a long-term goal of the field.
The main idea behind the surface code is to use topological quantum error correction. Each logical qubit exists in the form of several physical qubits. Thus, detecting errors and performing their correction is possible without the need for measuring the qubit state that results in its decoherence.
Surface code error correction is a very complicated process requiring precise coordination of processes. IBM’s processor works at a temperature near the absolute zero (15 millikelvins). Moreover, one has to ensure the perfect timing accuracy of microwave control in nanoseconds. Error rates below 0.1% provide the possibility for practical implementation of the process of quantum error correction.
Practical Significance of Low Logical Error Rates
The low logical error rates allow minimizing the resources used for the purposes of correction. At the level of the low rates below 0.1%, quantum error correction will consume less energy compared to the energy savings resulting from running the algorithms. At high error rates above 0.1%, quantum error correction consumes too many resources and becomes counterproductive.
Possible Immediate Uses
First of all, pharmaceutical industries have shown the most interest in this innovative development. As the modeling of molecular interactions plays an essential role in discovering medicines, scientists can take advantage of IBM’s new quantum computer. Simulating molecular interactions using classical computers is problematic due to the exponential scaling.
Quantum computers have no trouble simulating the interactions, and 1,000 logical qubits allow simulating proteins that classical supercomputers cannot handle.
Classical drug discovery technologies require approximations that lead to errors. As a consequence, drugs looking promising in simulations fail during laboratory tests. Therefore, the development of a quantum model capturing the real quantum interactions of a target protein and a medicine candidate is critical in improving the rate of successes in early stages of drug discoveries and significantly reducing the average 12-year drug development timeline.
Portfolio optimization, fraud detection, and similar problems with many variables interacting according to complex constrains belong to optimization tasks suitable for quantum computers. Financial institutions can use quantum computers to optimize their portfolios and detect frauds in financial markets.
Meanwhile, cryptography experts assess the threat level regarding the ability of quantum computers to break RSA encryption. Shor’s quantum algorithm provides an exponential speedup in factorizing large numbers compared to classical approaches. The 1,000-qubit milestone has created urgency in the post-quantum cryptography standardization process. In particular, NIST has established post-quantum standards for the first time in 2024.
As the result, organizations are under pressure to implement new encryption standards before the quantum computers become powerful enough to decrypt the existing communication networks.
Competition Between the Players
Of course, IBM is not alone on the market. Companies like Google (Quantum AI division), IonQ, Quantinuum, Microsoft, and a multitude of startups develop their quantum computers based on superconducting, trapped-ion, photonics, and topological qubit technologies. IBM’s competitor Google claimed the exponential improvement in error reduction after announcing the Willow superconducting processor.
The other major players in the field are trapped-ion processors of IonQ and Quantinuum. They allow achieving the best gate fidelities per qubit but face the challenges associated with scaling up. Meanwhile, Microsoft chose an alternative route developing quantum computers based on topological qubits – Majorana fermions that should be much more stable compared to regular qubits. However, the practical implementation remains problematic.
Besides these private ventures, NASA and the DARPA initiated special research programs in the field. Also, the European Union pledged to invest €1 billion into quantum computing through the EU Quantum Flagship program by 2027. The geopolitical component of the race for quantum supremacy is especially strong. Quantum supremacy is considered as a key national security issue.
Both the US and China mentioned quantum computing as one of the most promising technologies in their national security strategies.
Timeline to Practically Useful Quantum Computers
Although it is obvious that the 1,000-qubit breakthrough brings quantum computers much closer to real-life use, most specialists admit that we are still 5 to 10 years away from the point where the quantum computers can perform better than classical ones on practically valuable tasks.
The difference between ‘quantum supremacy’ (a quantum computer outperforming classical machines for a specific task) and ‘quantum advantage’ (quantum computer demonstrating advantages in solving practically valuable task) is crucial to understanding the state of affairs in the industry.
The previous demonstrations of quantum supremacy referred to artificially created computational tasks hard for classical machines. Thus, they have never had commercial value so far.
Therefore, it seems necessary to develop two aspects to create a practically usable quantum computer in addition to IBM’s milestone of 1,000 qubits. The first is increasing qubit counts up to millions in order to allow executing quantum error correction protocols. Another aspect concerns developing adequate quantum algorithms, which has been the weakest link for a long time.
Concluding Remarks
IBM achieved a historical breakthrough creating a quantum computer chip supporting up to 1,000 qubits with acceptable logical error rates. However, this does not imply that quantum computers can appear in our offices anytime soon. Yet, the development reduces the forecasted timeline considerably compared to the previous estimations.
This development along with advances in quantum software and hardware and the efforts of competitors create a situation in which the quantum computers transition from the research project stage to an industrial technology in the nearest decade becomes highly probable.
