The Quantum Engineering Initiative

The objective of this initiative is to establish a Quantum Engineering program at ETH with active industry participation. The program focuses on the practical implementation and application of quantum science and technology, such as quantum computing and simulation, quantum cryptography, or quantum sensing & imaging. The Quantum Engineering Initiative is a joint interdisciplinary endeavour by ETH's Electrical Engineering Department (D-ITET) and the Physics Department (D-PHYS). Under this initiative, ETH establishes a unique research program, trains a first generation of quantum engineers, and positions itself as the leading institution in quantum engineering.

To launch the Quantum Engineering Initiative at ETH we pursue two equally important initial steps:

to establish a new professorship in "Quantum Engineering" at D-ITET
to operate a Quantum Engineering Center (QEC) at ETH Zurich for efficiently promoting the development of technologically demanding aspects of quantum engineering such as device fabrication down to the atomic scale, materials research, control and read-out system development

The creation of a D-ITET professorship is key to this initiative. It fertilizes interest in quantum science among electrical engineers, form a nucleation centre for faculty interactions and draw engineering students into this emerging field. The new professor will entertain semester and master projects, establish new courses as well as a joint PhD program that engages both the physics and engineering communities, and pursue research in quantum engineering.

The Quantum Engineering Center employs a number of highly qualified and dedicated staff scientists and technicians to enable the realization of quantum hardware through the development of device fabrication technologies and materials as well as control and read-out systems. Through the centre, the expertise required to engineer solutions for quantum technologies is fruitfully assembled at to effectively address the interdisciplinary challenges at hand.

Background Information

Traditionally, quantum science has been a domain of fundamental research explored mostly by physicists. But as the field matures, more and more application areas and engineering research challenges emerge. The time is right to investigate and develop new technologies that capitalize on the working principles of quantum physics.

The quantum engineering program bears parallels with the history of electrical engineering. Until the end of the 19th century the study of electricity has been a subfield of physics and the first electrical engineering programs emerged in the 1880's at MIT, Cornell, and Darmstadt. ETH's electrical engineering department was initially joint with mechanical engineering and became independent in 1935. Thus, in analogy to electrical engineering, the emergence of quantum engineering programs at leading universities is only a matter of time. Indeed, a number of electrical engineering departments at major research universities world-wide have already begun to explore the opportunities of quantum technologies.

Although the initiative presented here is spearheaded by the departments of D-ITET and D-PHYS, the program will be promoted in other departments as well, e.g. D-MAVT, D-MATL, Chemistry, or Computer Science. The goal is that this initiative serves as an open platform and nurture ground for faculty and students interested in quantum engineering and technology.

The Setting

The economic growth which occurred during the last few decades has been tremendously influenced by our ability to process information at ever increasing rates and by our ability to transfer large amounts of information efficiently around the globe. These capabilities have not only influenced our industries and the ways we do business but also our personal lives and the ways we communicate and make use of information using modern technologies. At this point in time, the basis for information processing and communication technology is founded on concepts based on classical physics and information theory. However, as we know for more than 100 years, fundamentally, the world we live in is governed by the laws of quantum physics. Only about 30 years ago scientists started to pose the question, if information processing or communication could be different and more powerful, if it were to make use of the laws of quantum physics rather than the laws of classical physics. Indeed, it turns out that in a setting governed by the laws of quantum physics, processes that are unthinkable in a classical setting become possible. In particular, it turns out that certain classes of computational problems, which are hard to solve on a conventional computer, such as deciphering encrypted messages or searching large data bases, are in principle more efficiently solvable on a computer which makes use of the laws of quantum physics. Similarly, it turns out that using the laws of quantum physics it is in principle possible to communicate securely over large distances without being prone to eavesdropping by an adverse party. The basic theoretical foundations for harnessing quantum physics in information processing and communication have been laid out thoroughly throughout the last two decades.

Only fifteen years ago, harnessing the great potential of quantum physics in the context of information processing and communication seemed like science fiction. Many of the practical suggestions scientists made in those days were righteously considered extremely challenging to realize. However, by now, researchers in many domains of physics, information science and engineering have physically realized devices and systems which make use of the laws of quantum physics to process and communicate information. For example, many basic elements of a computer processing information quantum mechanically, a so called quantum computer, have been realized in various labs around the globe. These include the realization of information carriers (bits) which function quantum mechanically (qubits), techniques to initialize, to write to and to read-out information from qubits, and the operation of logical operations between qubits which allow executing simple programs (algorithms) on these systems. Indeed, it has been demonstrated in a number of different systems that various algorithms can be executed more efficiently using a computer based on quantum physics than using a classical computer.

At the current state of the art the basic properties of the systems considered for realizing quantum hardware are understood at a great level of detail. Now, it becomes increasingly more important to develop quantum systems which are capable of harnessing their full potential and scale to a practically relevant size. Interestingly, some of the hardest problems appear when investigating appropriate system concepts that finally lead to the design of viable quantum systems. Developing corresponding basic elements and integrating them into such a system is a formidable task, not only on the level of quantum physics but also on the level of engineering science.

At ETH Zurich, the potential of quantum science and technology has been recognized a number of years ago. ETH Zurich has first supported an innovation initiative starting from 2006 and then a multiple-group research effort in Quantum Systems for Information Technology. Since 2011 ETH Zurich is the leading house of a Swiss wide research effort assembled in a National Center of Competence in Research (NCCR) on the topic of Quantum Science and Technology (QSIT).

At this point in time, the development of quantum information and communication technologies for applications requires the field of basic research on quantum science and technology to be complemented by an increasingly important effort in quantum engineering. Many of the foremost challenges at hand are related to engineering quantum systems beyond the demonstration level. Here the goal is to make them technologically viable and to explore first applications with a potential commercial interest.

Researchers leading in the field of quantum sciences have realized that for continuing the development it is required to make a conscious step from the extremely successful activities in quantum sciences into a new era of quantum engineering. That this step bears a high level of potential is not only realized at ETH but also at other leading centres for quantum technologies. These include TU Delft (The Netherlands) where the founding of a external page QuTech Centre has recently been announced or the University of Chicago, which is starting a new department for external page Molecular Engineering with a strong focus on quantum technologies. In the following we describe how ETH Zurich, one of the leading institutions for quantum sciences, secures a leading spot in the global effort to transform information processing and communication techniques with engineered quantum technologies by creating a new Quantum Engineering Initiative.

Quantum Engineering at ETH Zurich

To enable the realization of viable hardware for quantum enabled information processing and communication technologies, ETH Zurich supports a concerted effort in Quantum Engineering. The new ETH Zurich Quantum Engineering Initiative is based on three complementary pillars which are outlined here and discussed in more detail below.

The Quantum Engineering Center: To enable the realization of quantum technologies and their deployment for applications requires a concerted development of quantum engineering capabilities at the intersection of nanoscience, atomic physics, devices and systems. This is only possible by assembling a set of scientists and engineers gaining experience in addressing these challenges and finding viable solutions. This highly interdisciplinary and challenging task is best implemented by forming a group of excellent researchers and developers associated with a Quantum Engineering Center, the function and operation of which is further detailed below.
Education in Quantum Engineering: Harnessing the full potential of quantum technologies requirs e a strong educational effort. Teaching the surprising and often counterintuitive principles and consequence of quantum mechanics to engineering students is a major source of inspiration to them. To enable the transformation from a mainly physics-based research effort in quantum science to a joint approach to quantum technologies we will create a new Quantum Engineering Curriculum aimed at students in the domains of electrical engineering, computer science, materials and physics.
Quantum Engineering Faculty: To establish expertise in quantum science, technology and engineering at ETH, quantum science is brought into the labs of engineers and the elements of quantum technology are integrated into the curriculum of engineering students. To achieve these goals a professorship in quantum engineering is in the process of being established at the electrical engineering department (D-ITET). This creates the backbone needed for a long-term development of quantum engineering expertise at ETH Zurich.

The Quantum Engineering Center
Webpage of the Quantum Engineering Center

One of the central pillars of quantum engineering is computation. The department of physics at ETH currently pursues research on different platforms for quantum computation. Significant momentum for the quantum engineering initiative is gathered in scaling-up two of the currently most promising and scalable platforms, namely quantum computing based on ions in traps and on superconducting electronic circuits. The first platform is based on ions trapped in ultra high vacuum which are manipulated with Lasers, radio and mcirowave frequency electromagnetic fields. The second platform is based on lumped and distributed circuit elements that are familiar to engineers, it is compatible with standard engineering concepts and approaches, and it provides a fertile ground for collaborative efforts.

Quantum Information Science and Technology

Quantum information science pursues the goal of drastically enhancing the capabilities of information processing and communication systems by making use of the laws of quantum physics. Building real world quantum machines promises to more efficiently solve computationally hard problems and to provide means for secure communication.

In quantum information science a number of algorithms have been invented already, which are proven to be more efficient in solving hard problems than any known classical algorithm. These include factoring large numbers (Shor’s algorithm), searching large unsorted data bases (Grover’s algorithm) and simulating large quantum systems (external page as suggested by Feynman). While many physicists believe that using quantum computers to simulate and understand physical systems, such as large molecules in chemical or even biological settings and complicated solid state systems, is the most interesting application, it seems also reasonable to expect that other interesting and useful algorithms will be developed once the hardware for a large enough quantum computer is available to try them out.

Furthermore, it is important to appreciate that promising non-computing related applications will result from research on quantum information processing. Examples include the investigation of novel high bandwidth and secure communication principles, the development of atomic scale devices, the development of ultra-precise clocks for metrological applications, the creation of random number generators, and the realization of low-noise-amplifiers reaching the lowest limits of added noise as imposed by quantum physics.

Choosing a Physical System to Develop Quantum Hardware

A number of competing approaches to realize systems capable of processing information quantum mechanically are vigorously pursued by a diverse community of academic, governmental and industrial researchers worldwide. Although a winning hardware technology for building such machines has not been singled out yet, systems based on singly ionized atoms (ions) [as pursued at ETH by Jonathan Home] or on integrated superconducting electronic circuits [Andreas Wallraff] show most promise to lead towards a viable quantum information processor. Other systems pursued in this context include semiconductor quantum dots [Atac Imamoglu, Klaus Ensslin], color centers in solids [Christian Degen], and nuclear magnetic moments or photons [external page Nicolas Gisin, Geneva].

Superconducting electronic circuits are a prime contender for realizing hardware for future quantum information processors. They are based on micro- and nanofabricated integrated electronic circuits. The circuits, although they are macroscopic in size, do have properties that are solely governed by the laws of quantum physics, when operated in an appropriately engineered environment. Interestingly, using approaches known from electrical engineering, quantum systems with the desired properties can be designed and realized with a large degree of control over the classical and quantum properties of the system. The micron and sub-micron components of these circuits are fabricated using lithographic techniques closely related to those used in semiconducting integrated circuit technology. This makes these circuits particularly well suited to deploy techniques explored in the engineering domain for optimizing, integrating and eventually scaling up these circuits. In addition, developing device-fabrication techniques using suitable low-loss materials that preserve the fragile quantum properties of the circuits is an important and challenging task.

Main Challenges for Pursuing Quantum Based Technologies

The current state of the art allows for the realization of superconducting circuits incorporating on the order of 10 quantum degrees of freedom, which are qubits acting as information carriers and oscillator modes acting as quantum buses for information transfer. While the focus of quantum engineering is wider, the first development will concentrate on superconducting circuit-based quantum technologies. For these systems incorporating a larger number of qubits faces several important challenges:

The creation of multi-qubit circuits in scalable architectures which maximize desired control couplings while minimizing unwanted cross-couplings leading to errors: Quantum coherent circuits require good isolation from each other and from their control and read-out circuitry while maintaining addressability. This demands careful engineering of the electromagnetic environment of the circuits to exclude low frequency noise, maintain coherent control at GHz frequencies and nanosecond timescales, and avoid detrimental infrared radiation.

The realization of hard- and software enabling quantum control in multi-qubit scalable systems consisting of several tens to hundreds of quantum circuit elements: Quantum information processing with superconducting electronic circuits relies on the accurate coherent control of circuit elements using amplitude and phase controlled nanosecond timescale microwave frequency pulses. To perform these tasks scalable, economic control systems have to be designed and realized, and new approaches to multiplexing, error correction, and sensitive detectors have to be developed to create large scale systems.

The improvement of coherence properties of qubit systems through device design, fabrication techniques and materials development: Creating large scale quantum coherent electronic circuits requires dedicated device fabrication techniques. In contrast to conventional electronic circuit fabrication, ultra-low loss materials have to be used to maintain the fragile quantum properties of the circuits. Device fabrication techniques to be developed have to preserve the low-loss while being amenable to scaling on the required level. At the same time scaling requires the development of fabrication techniques maintaining the essential isolation of circuit elements from each other and their control and read-out circuitry. To achieve these tasks it requires the development of specific processes and dedicated fabrication tools.

Course of Action

The Quantum Engineering Center

ETH Zurich possesses a very high potential to competitively and effectively develop viable solutions for the main challenges faced in the development of quantum information processing systems. In addition to excellent and dedicated students and faculty, which are plentiful at ETH Zurich, the continued contributions of highly trained and motivated research and engineering staff are essential to achieve the goal of realizing a platform for quantum technologies.

We are in the process of assembling a strong team of permanent scientific/engineering staff (having a PhD degree and Postdoctoral experience) to form the nucleus for a Quantum Engineering Center. These staff members work on their projects pursuing the development of quantum hardware in collaboration with students from affiliated research groups. It is important that the scientific/engineering staff positions can be permanent to be attractive to candidates fulfilling the high requirements for such a platform. In addition, contributions of technical staff in the three main areas of micro/nano-fabrication, analog/digital electronics and mechanics enables the technical realization of the projects. Technical expertise in device fabrication and materials is essential for advancing the development of quantum devices and guaranteeing the continued improvement of the quantum properties of the circuits. The development of analog and digital control and measurement electronics are essential for scaling and integrating quantum circuits while maintaining complexity and cost at a controllable level. Mechanical aspects include the operation of low-noise, low-temperature environments for quantum circuits, the development of device packaging and device interfaces. The effort will also be supported by one administrative/management staff member.

The allocation of space in a single location is benfitial for the success of the Quantum Engineering Center. This space will serve as an incubator: it will fuse students from different departments together and function as an interactive platform to exchange ideas and establish collaborations. Communication and active participation and engagement is key to the success of the quantum engineering initiative. Engineers learn the principles of quantum science from physicists and, vice versa, physicists develop an understanding of fabrication, production, and packaging from engineers. Such a hand-in-hand process is best posed for transitioning quantum technology from the laboratory into potential products.

In a first step we establish laboratory space affiliated with the existing groups at the ETH Hoenggerberg Campus. This laboratory serves as a nucleus for beginning to establish and strengthen connections between engineering researchers and quantum science and technology researchers. Those with an interest positioned at the interface between science and engineering are actively encouraged to play an important role in the development of both hard- and software for future quantum information systems. Such bottom-up activities are enhanced by fruitful collaborations between existing staff and faculty in physics and engineering departments.

The Quantum Engineering Center hosts a team of PhD students, postdocs and permanent research and engineering staff developing the technological platform for quantum technologies by creating, testing and integrating new quantum devices.

Quantum Engineering Curriculum

Under the umbrella of this initiative a new curriculum in Quantum Engineering will be created aiming at students in the domains of electrical engineering, computer science, materials and physics. In a first step, such a well arranged aggregate of courses can be offered in existing master Programs, e.g. in D-ITET and D-PHYS. Currently, the D-ITET bachelors program does offer only limited courses in quantum mechanics and therefore engineering students not yet sufficiently prepared for an MS course in Quantum Engineering. A solution is to offer as part of such an aggregate of courses a basic, engineering-oriented quantum mechanics course, similar to the one established by Prof. Norris in D-MAVT (151-0966-00L), which turned out to be well attended by engineering students. Prof. Norris received the Credit Suisse Award for Best Teaching 2015.

In further steps, a set of courses dedicated to PhD students or even a dedicated Master program will be considered.

Professorship in Quantum Engineering

A main priority of this initiative is the installment of a Quantum Engineering Professorship at D-ITET. This professorship will strengthen the engineering aspects of quantum technologies and nurture the active involvement of engineering students and researchers. The professorship will decisively contribute to the long-term goal of realizing quantum computing technology at ETHZ. However, quantum engineering goes beyond computing: the ongoing miniaturization of integrated circuits and the downscaling of circuit elements is reaching the limits where quantum effects come naturally into play. While it is necessary to take these effects into account in the design of future components and systems, it can be expected that disruptive ideas will emerge from novel concepts, such as the control of single quantum excitations. For example, a qubit does not pick up noise during evolution, only at the measurement stage. This is in stark contrast to a classical system, which always picks up noise during evolution; Integrating the surprising and often counterintuitive principles and consequence of quantum mechanics into the research and education profile of D-ITET will be a major source of inspiration to the whole department, i.e. faculty, researchers and students.

Examples of potential research topics in quantum engineering and quantum information technology are

quantum photonic technologies for communication, sensing, simulation and computation
integrated quantum circuits and quantum technology platforms
quantum random number generators
quantum limited detection / sensing (photon detectors, multiphoton tomography, quantum imaging)
quantum metrology
quantum crytopgraphy
quantum devices, components and circuits (single atom devices, tunnel diodes, tunnel transistors, quantum point contacts, single-electron transistors)

The program and infrastructure created as part of the Quantum Engineering Center, outlined in the previous section, serves as an attractive research platform for the new hire and allows the new professor to efficiently build up momentum.

Broader Impact

Incorporation into existing activities at ETH Zurich

The Quantum Engineering Initiative integrates very well into the ETH Zurich based activities in Quantum Science and Technology which are solidly anchored in the department of physics (D-PHYS) through more then 10 research groups and also represented by groups in other departments (D-ITET, D-CHAB). Quantum Science and Technology (QSIT) are also incorporated into the Swiss scientific community through the very successful SNF-funded NNCR-QSIT with ETH Zurich as a leading house. The proposed activity combines well with the general focus research areas of ETH Zurich and also make important use of the existing nano- and micro-fabrication facilities FIRST and BRNC.

Benefits to ETH Zurich, Switzerland and society

A successful implementation of this initiative presents ETH Zurich with the opportunity to significantly strengthen its position as a leading institution in the extremely competitive international research area of quantum information science. ETH Zurich will play a leading role at the highest international level in the development of quantum information processing hardware. This activity has the potential to re-enforce Switzerland’s position as a leading nation in the creation of novel technologies, in particular those enabled by quantum technology. The effort focuses on the development of superconducting circuit-based and ion-trap technologies but will be beneficial to quantum information research on atom- or semiconductor-based and systems, e.g., through collaborations focused on control and read-out hard- and software. Also other domains such as electron spin resonance and precision spectroscopy, pursued in D-CHAB, benefit. The technologies to be developed are not limited to quantum information processing and communication only. They have the potential to expand into the direction of control and measurement systems enabled or enhanced by quantum physics, including quantum amplifiers, detectors, radiation sources and sensors. Such systems and components are traditionally developed in the engineering disciplines. In the future quantum systems are expected to play an important role also in these domains of engineering. The ongoing developments have already led to significant improvements in measurement and control instrumentation, some of which are already being commercialized with Swiss start-up companies, e.g. external page Zurich Instruments. The commercialization of diverse quantum technologies certainly has the potential to create novel opportunities similar to the ones created by external page Sensirion, when they integrated novel sensing technologies with integrated CMOS electronics in creative and commercially successful ways. Moreover, the exploration of quantum physics for novel applications in the context of information processing and communication and beyond allows for the development of novel tools and devices. Finally, the continued exposure of scientists, engineers and eventually also the general public to concepts of quantum physics, provides the potential to gain a deeper understanding of the sometimes strange and unintuitive features of quantum physics. Such understanding enables the development of novel quantum technologies in the long term.