Classical computers just won't cut it when it comes to tackling the greatest challenges in biology and medicine. Even accurately simulating the relatively simple caffeine molecule, far simpler than DNA or even proteins, would take an impossibly large classical computer. That's why we need a paradigm shift in the field of computing, like a shift from the steam locomotive to a starship's warp drive. That's why we need quantum computers. At IBM Quantum, we've already started building quantum computers based on superconducting transmon qubit technology, and have been making this transformative technology available to the world. Back in 2016, we made history when we put our quantum computers on the Cloud for anyone from enterprise developers to students to program. Last fall, we announced an aggressive roadmap toward building a 1121-qubit device by 2023. However, even that device will not be large enough to solve science's greatest challenges. That will require fault-tolerant quantum processors containing potentially millions or even billions of qubits working together. The technology required to build a processor with a few million superconducting qubits will likely surpass the limits of dilution refrigerator scaling (Figure 1), so we have to come up with alternative ideas for scaling up our devices efficiently. We think that constructing the fault-tolerant quantum computers of the future will require a distributed approach similar to today's supercomputers, where smaller processors each in their own fridge share quantum information coherently and without loss to tackle problems in parallel. This will only be possible if we can develop quantum interconnects to link processors together into a quantum intranet. This requirement for a quantum intranet is distinct from the more commonly discussed context of a quantum Internet. Quantum communications advances typically center around data transfer security such as long-distance entanglement and quantum key distribution. IBM has long been involved in this field; IBM researchers debuted the BB84 QKD protocol in 1984 [1], for example. However, we must not lose sight of the fact that short-distance quantum interconnect technology may play a key role in extending computational systems to a scale sufficient for solving practical problems. A quantum Internet connecting and interfacing such scaled quantum computers would follow as a next step to enable new applications. [2]. Quantum interconnects capable of supporting our vision of a quantum intranet will require fundamental advances in physics. The no-cloning theorem makes it impossible to convert an arbitrary, unknown quantum state into classical bits and then use these bits to recreate that exact state elsewhere, so we must devise schemes that stay coherent as we transfer quantum information from the states of superconducting qubits onto the states of photons, transmit these photons over wires, and recreate the quantum state on the superconducting qubits of another processor. At the same time, the microwave photons we use to manipulate and read out our superconducting qubits require wiring overheads, and a significantly different cryogenic infrastructure to permit coherent transfer of quantum states even over short distances. Hence, converting microwave photons into optical photons allows for low-loss quantum state transfer through fiber optic infrastructure that the telecom industry has spent decades maturing. Academic groups have been working for over a decade to transfer quantum information from microwave to optical photons in a coherent manner with a variety of systems and mechanisms, and while this has not been conclusively demonstrated, progress has been made [3]. At IBM Research's Thomas J. Watson Research Center in Yorktown Heights, NY, we have been developing a silicon-germanium microwave-optical transducer (funded by the Army Research Office and the Laboratory for Physical Sciences) that's integrated with our own transmon qubit platform. Meanwhile, our IBM Research lab in Zurich is exploring a different platform, to develop piezo-optomechanical transducers in gallium phosphide. Implementing and perfecting each of these solutions will be challenges on their own—plus, we must devise distributed error correcting codes to run on these systems. IBM Quantum “super-fridge” photo: https://flic.kr/p/2jHrEGw. IBM is developing a suite of scalable and increasingly larger and better processors, with a 1000-plus qubit device targeted for the end of 2023. In order to house even more advanced processors to the thousands and eventually million-plus qubit systems of the future, the IBM Quantum team is building a dilution refrigerator larger than any currently available commercially. (Credit: Connie Zhou for IBM) Our primary research focus is in scaling up transmon qubit processors, but the issues surrounding scale-up are important to every qubit architecture. We think that quantum interconnect research, and a quantum intranet, will be the likely solution to scale-up across the field. The community has already deemed quantum interconnects as "crucial for sustained development of a national quantum science and technology program" [4]. Other recent work involving connecting spatially separated qubits with microwave includes Zhong, Y. et al.’s “Deterministic multi-qubit entanglement in a quantum network,” [5], and Magnard, P. et al.’s “Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems.” [6] Given the importance of these devices, and the impact of scale, we cannot tackle these challenges alone. In August of last year, the US Department of Energy announced that it would allocate up to $625 million in funding over five years to support multidisciplinary Quantum Information Science (QIS) Research Centers. We expect that the work carried out at these centers will be essential to realizing the quantum intranet. Specifically, IBM Quantum will work with the Q-NEXT center led by Argonne National Laboratory to co-design technological building blocks and system needs that will allow us to realize these quantum interconnects. The IBM Quantum team is developing quantum computers because we think that these devices have the capability to change the world, but seeing them through to completion will take innovative solutions to physics problems that physicists have never faced before. If we can realize quantum interconnects and a quantum intranet, then we think we have a clear path to making these devices, and their abilities, a reality.
Classical computers just won't cut it when it comes to tackling the greatest challenges in biology and medicine. Even accurately simulating the relatively simple caffeine molecule, far simpler than DNA or even proteins, would take an impossibly large classical computer. That's why we need a paradigm shift in the field of computing, like a shift from the steam locomotive to a starship's warp drive. That's why we need quantum computers. At IBM Quantum, we've already started building quantum computers based on superconducting transmon qubit technology, and have been making this transformative technology available to the world. Back in 2016, we made history when we put our quantum computers on the Cloud for anyone from enterprise developers to students to program. Last fall, we announced an aggressive roadmap toward building a 1121-qubit device by 2023. However, even that device will not be large enough to solve science's greatest challenges. That will require fault-tolerant quantum processors containing potentially millions or even billions of qubits working together. The technology required to build a processor with a few million superconducting qubits will likely surpass the limits of dilution refrigerator scaling (Figure 1), so we have to come up with alternative ideas for scaling up our devices efficiently. We think that constructing the fault-tolerant quantum computers of the future will require a distributed approach similar to today's supercomputers, where smaller processors each in their own fridge share quantum information coherently and without loss to tackle problems in parallel. This will only be possible if we can develop quantum interconnects to link processors together into a quantum intranet. This requirement for a quantum intranet is distinct from the more commonly discussed context of a quantum Internet. Quantum communications advances typically center around data transfer security such as long-distance entanglement and quantum key distribution. IBM has long been involved in this field; IBM researchers debuted the BB84 QKD protocol in 1984 [1], for example. However, we must not lose sight of the fact that short-distance quantum interconnect technology may play a key role in extending computational systems to a scale sufficient for solving practical problems. A quantum Internet connecting and interfacing such scaled quantum computers would follow as a next step to enable new applications. [2]. Quantum interconnects capable of supporting our vision of a quantum intranet will require fundamental advances in physics. The no-cloning theorem makes it impossible to convert an arbitrary, unknown quantum state into classical bits and then use these bits to recreate that exact state elsewhere, so we must devise schemes that stay coherent as we transfer quantum information from the states of superconducting qubits onto the states of photons, transmit these photons over wires, and recreate the quantum state on the superconducting qubits of another processor. At the same time, the microwave photons we use to manipulate and read out our superconducting qubits require wiring overheads, and a significantly different cryogenic infrastructure to permit coherent transfer of quantum states even over short distances. Hence, converting microwave photons into optical photons allows for low-loss quantum state transfer through fiber optic infrastructure that the telecom industry has spent decades maturing. Academic groups have been working for over a decade to transfer quantum information from microwave to optical photons in a coherent manner with a variety of systems and mechanisms, and while this has not been conclusively demonstrated, progress has been made [3]. At IBM Research's Thomas J. Watson Research Center in Yorktown Heights, NY, we have been developing a silicon-germanium microwave-optical transducer (funded by the Army Research Office and the Laboratory for Physical Sciences) that's integrated with our own transmon qubit platform. Meanwhile, our IBM Research lab in Zurich is exploring a different platform, to develop piezo-optomechanical transducers in gallium phosphide. Implementing and perfecting each of these solutions will be challenges on their own—plus, we must devise distributed error correcting codes to run on these systems. IBM Quantum “super-fridge” photo: https://flic.kr/p/2jHrEGw. IBM is developing a suite of scalable and increasingly larger and better processors, with a 1000-plus qubit device targeted for the end of 2023. In order to house even more advanced processors to the thousands and eventually million-plus qubit systems of the future, the IBM Quantum team is building a dilution refrigerator larger than any currently available commercially. (Credit: Connie Zhou for IBM) Our primary research focus is in scaling up transmon qubit processors, but the issues surrounding scale-up are important to every qubit architecture. We think that quantum interconnect research, and a quantum intranet, will be the likely solution to scale-up across the field. The community has already deemed quantum interconnects as "crucial for sustained development of a national quantum science and technology program" [4]. Other recent work involving connecting spatially separated qubits with microwave includes Zhong, Y. et al.’s “Deterministic multi-qubit entanglement in a quantum network,” [5], and Magnard, P. et al.’s “Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems.” [6] Given the importance of these devices, and the impact of scale, we cannot tackle these challenges alone. In August of last year, the US Department of Energy announced that it would allocate up to $625 million in funding over five years to support multidisciplinary Quantum Information Science (QIS) Research Centers. We expect that the work carried out at these centers will be essential to realizing the quantum intranet. Specifically, IBM Quantum will work with the Q-NEXT center led by Argonne National Laboratory to co-design technological building blocks and system needs that will allow us to realize these quantum interconnects. The IBM Quantum team is developing quantum computers because we think that these devices have the capability to change the world, but seeing them through to completion will take innovative solutions to physics problems that physicists have never faced before. If we can realize quantum interconnects and a quantum intranet, then we think we have a clear path to making these devices, and their abilities, a reality.
There are signs that we are approaching a technical revolution that might take humankind’s computational capabilities to a new level. Quantum Computing leverages the principles of quantum mechanics, enabling the computational power to solve specific problems currently intractable for classical computers (e.g., cracking cryptographic keys). Since we are getting to a point where we can no longer build smaller, more powerful, more efficient devices with conventional methodologies, we need to think of new ways for technological progress. The manufacturing of microchips is reaching its limits in the use of traditional architectures. Hence, new and more advanced technologies need to address the challenges of increasing energy consumption and data processing. Connectivity, scalable architectures and concepts like Cloud Computing and Software-as-a-Service have already helped to scale computational-intense applications in the last years and have attracted the interest of IS researchers (e.g., Benlian et al. 2009 ; Benlian et al. 2018 ; Messerschmidt and Hinz 2013 ). Looking ahead to the next generation, computing will comprise technologies that enable high-performance applications far beyond today’s possibilities. One prominent example with a disruptive potential is Quantum Computing. While there are abundant open questions and directions for further developments, researchers in this area have made substantial progress in the last decade, indicating that, after medical imaging, lasers, and superconductors, another quantum-technological innovation might be approaching. We, therefore, intend to provide an overview of the current state of Quantum Computing research and outline how this new technology might stimulate research in Information Systems.
"Can we do this with a new type of computer - a quantum computer?". This famous quotation of the brilliant Richard Feynman within a conference talk on "Simulating physics with computers.” is often reverently praised as the origin of the field of quantum computing. The idea was to use quantum mechanical systems itself to simulate "Nature", which is inherently quantum mechanical. Now, 43 years later, the theoretical framework of how such a computer can operate has been developed. Two main important concepts for a potential quantum supremacy, superposition and entanglement, have been exploited to design quantum algorithms to significantly speed up certain tasks. Yet, the specific hardware implementation is still far from being certain, in fact the race between the most promising platforms such as superconducting qubits, bosonic codes, cold atoms, trapped ions, optical computing as well as spin qubits has recently intensified. If one also includes the most mature applications of quantum communication technologies, secure quantum key distribution and quantum random number generators, as part of a quantum information technology ecosystem, we are confronted with a plethora of different materials, concepts, and also operation frequencies. While superconducting qubits, bosonic codes and spin qubits work in the regime of approximately 5 GHz and are controlled by electrical fields, trapped ions, cold atoms, and optical quantum computing operate with light in the infrared or visible range. Consequently, a quantum frequency converter or microwave-optic transducer is required to interface the different frequency domains or establish a long-range network connection with suitable telecom fibers. In fact, the combination of different frequency regimes is also an essential part in our classical modern communication network, where computations are performed in electrical circuits and the information exchange over longer distances happens via optical fibers. However, the specific challenges specific to building a quantum computer, also apply to the development of such a quantum frequency transducer: 1) As we deal with single excitations as the carrier of information, i.e. the smallest possible quantity, the signal can easily be corrupted by other noise sources which needs to be avoided by all means. This is also the reason why microwave quantum computers operate at temperature environments close to zero temperature (< 0.1 Kelvin) to avoid corruption by thermal noise. 2) The frequency interface generally needs to preserve the phase of the signal as an essential part of the quantum state. And 3) Quantum signals cannot be copied which would be a typical strategy to account for errors in classical computers. And finally, there is a challenge specific to microwave-optic transducers: While quantum computers are operating in one specific frequency domain, microwave-optic transducers combine microwave and optical fields in one device. This results in the particular challenge that high-energy optical radiation, which is usually well-shielded from superconducting microwave quantum processors, are now an essential part of the device. The concomitant optical radiation in the operating transducer will inevitably have a detrimental effect on the superconducting microwave components. Together with the requirement of minimal background noise for quantum-limited operation as described above, v heating from the absorption of optical photons within the same device where single microwave excitations are processed forms a formidable challenge. This thesis aims to address this challenge by developing microwave-optic transducers where the impact of optical absorption on superconducting circuits in general and superconducting qubits specifically can be mitigated. In our first approach, we developed a compact device with optimized interaction strengths between the different frequency domains. This minimizes the optical powers used for transducer operation and thus the optical absorption heating. This work was - to the best of our knowledge - the first comprehensive noise study, in an integrated microwave-optic transducer. Unfortunately, we saw that the optical absorption heating added noise way above a single excitation. Consequently, a potential quantum signal would have been buried in the noise, added by the transduction. Building on this insight, we utilized a three-dimensional microwave-optic transducer instead of an integrated device. The larger heat capacity of the macroscopic device with a size of a few millimeters can absorb a larger fraction of the optical heating before it increases the temperature of the device. This allowed us to interface the transducer directly with a superconducting qubit to readout the qubit state in a novel all-optical manner. We showed that the microwave-optic transducer can be operated in a regime in which optical fields don’t harm the sensitive qubit. This is an important prerequisite for the operation of microwave-optic transducers in conjunction with microwave quantum processors and brings the integration and seamless orchestration of different frequency components in a quantum network a step closer.
The field of quantum computing has evolved into a large interdisciplinary community where significant resources are invested worldwide. As a result, accelerated progress is achieved and we are at the beginning of a new age of computation, developing programmable quantum systems towards universal quantum computers. Quantum computers promise to solve certain mathematical problems that are intractable to classical computers. Quantum computing systems are built from the bottom up reaching the limits of what can be classically simulated. The IBM Quantum Development Roadmap describes our vision of creating a quantum computing ecosystem delivering quantum applications through the cloud. This requires developing the entire quantum computing stack starting from the qubit and quantum processor technology, control electronics to software, algorithms and applications for quantum computing, implemented in the cloud and integrated with high performance computing. In this presentation the recent developments of our quantum computing systems and the scientific advances that enabled scaling superconducting quantum processors to 127 qubits are presented. Besides scale, also quality and speed will be discussed building the key metric for measuring the performance of quantum computation. Examples of applications where the computational power of quantum computing could make a difference are provided.
Quantum computing is a paradigm shift in computational science, where computational tasks that cannot be computationally tackled with binary computing systems can be tackled using quantum mechanics principles, including superposition, entanglement, and quantum interference. The present paper gives a comprehensive summary of the present condition of quantum computing, including the most advanced hardware systems, such as topological qubits, photonics processors, trapped-ion systems and superconducting qubits, and their corresponding advantages and technical challenges. Also, quantum algorithms, including the Quantum Approximate Optimization Algorithm (QAOA) and the variational quantum eigen solvers (VQE), include a summary of the first algorithm, Shor's factorization method, and the second algorithm, Grover's search algorithm. Applications of such algorithms are evaluated in such areas as financial modeling, machine learning, material science, drug discovery, and cryptography. Taking into account the information provided by large research facilities and technology firms, the conditions under which quantum systems can outperform conventional technology, such a concept as quantum advantage is given specific focus in this review. Moreover, this paper pays particular attention to the key barriers to effective implementation, such as qubit decoherence, large error rates, scalability issues, and the lack of fault-tolerant quantum devices that can be sold commercially. Regarding the noisy intermediate-scale quantum (NISQ) devices that are expected to be available in the near future, we discuss novel approaches to quantum error correction, especially surface code and concatenated code. The quantum software industry, such as IBM Qiskit, Google Cirq, and Microsoft Q, and an evaluation of quantum workforce and research facility readiness across the globe is also discussed. In the end, this work highlights essential potential future paths, such as standards for post-quantum cryptography, hybrid quantum-classical computation, quantum networking and the quantum internet, and the long-term aims for universal fault- tolerant quantum computers. The review should provide researchers, graduate students, and practitioners with a systematic and up-to-date base to understand the fast-growing discipline of quantum computing and its extensive implications on science and business.
Abstract Quantum computing leverages fundamental quantum-mechanical phenomena—most notably superposition, entanglement, and quantum tunneling—to perform computations in ways that differ fundamentally from classical digital processing. Compared to conventional computing architectures, quantum systems promise significant reductions in computational time and potentially lower energy consumption for specific classes of problems. These advantages, combined with advances in nanoscale engineering and the slowing of traditional hardware scaling trends such as Moore’s Law, have led to substantial commercial and national-security-driven investments in quantum technologies over the past decade. A major milestone was reached when Google announced the experimental demonstration of “quantum supremacy,” showing that a quantum processor could execute a specific computational task infeasible for a classical supercomputer within practical time constraints. Although the demonstrated problem had no immediate practical application, this achievement marked a crucial step toward the development of quantum systems capable of delivering real-world computational advantages and provided a more precise technical framing of the concept of quantum advantage. Despite the fact that the mathematical foundations, programming models, and principal quantum algorithms were established in the 1990s, quantum computing remained largely confined to a specialized research community for decades. Today, the increasing accessibility of cloud-based quantum hardware calls for a broader dissemination of implementation-oriented knowledge among researchers and practitioners in computer science, software engineering, and related fields. The quantum programming paradigm differs fundamentally from classical programming models and often relies on physical and algebraic notations that may pose barriers to traditionally trained computer scientists. This series of articles provides a self-contained and concise introduction to quantum computing and its core algorithms, with a strong emphasis on practical implementation. Given that real quantum processors—such as those accessible via the IBM quantum ecosystem—are now available as cloud services, experimental validation can be conducted both on simulators and on actual hardware for small-scale inputs. While other platforms such as Rigetti and IonQ also offer cloud-based quantum computing services, this review focuses exclusively on the IBM quantum computing ecosystem.
Abstract Quantum computers represent a transformative frontier in computational technology, promising exponential speedups beyond classical computing limits. IBM Quantum has led significant advancements in both hardware and software, providing access to quantum hardware via IBM Cloud® since 2016 and achieving a milestone with the world’s first accessible quantum computer. This paper explores IBM’s journey in quantum computing, focusing on its contributions to both hardware and software, as well as the development of practical quantum computers. We trace the evolution of IBM Quantum’s processors, from the early canary processors to the milestone of surpassing the 1000-qubit barrier. In addition to these technological strides, we delve into the practical applications of quantum computing, particularly within nine key industries: airlines, banking, healthcare, electronics, life sciences, and more. We also explore IBM Quantum’s case studies and strategic partnerships with organizations such as Boeing, CERN, ExxonMobil, and Cleveland Clinic, which are helping to bridge the gap between theoretical research and real-world applications. Further, we examine the key challenges and solutions in scaling quantum systems and achieving fault tolerance, highlighting IBM’s efforts toward building practical, fault-tolerant quantum systems capable of addressing real-world problems.