A Glimpse into Quantum Physics

October 13, 2022 – Reading time: 7 minutes

As a technology and innovation consultancy, INVENSITY relies on the unique expertise of its employees, who work together in teams to achieve excellent results for our clients. In order to fully meet the requirements of a diverse market, our teams represent equally diverse areas of expertise. Thus, we have always had a certain number of physicists among our experts.

In today’s interview, Dr. Pascal Macha, a quantum physicist, and INVENSITY alumnus, shares his thoughts. Christopher Seinecke, Managing Director of INVENSITY, asked him about quantum physics, his career, and where his knowledge comes into play in development projects.

Christopher Seinecke: Ok, so who are you?

Dr. Pascal Macha: I am an INVENSITY Alumnus and a quantum physicist. In my current position as a senior researcher at Silicon Quantum Computing based in Sydney, Australia, my mission is to get the first quantum computer in silicon working.

Christopher Seinecke: What did you do at INVENSITY?

Dr. Pascal Macha: My journey started as a business consultant and led me to become the first office leader at our Hamburg branch. In these roles, I was responsible for acquiring new clients specifically focusing on the high-technology sector.

Christopher Seinecke: Everybody talks about quantum physics. What is that exactly? What makes it so different?

Dr. Pascal Macha: Well, let me put it this way: Physics is the one thing we all understand the best. When you throw a ball to someone who catches it, both of you must calculate all the classical physics in your head, and you do it so well that you don’t even have to think about it!

That is different for quantum mechanics; quantum mechanics is not part of our everyday experience but governs everything that is very small and is one of the reasons that the table that we are sitting at doesn’t fall apart. So, while it is very important, we do not have any intuition about it. And that’s what I believe a quantum physicist is: someone who is comfortable working with the uncertain and unintuitive.

Christopher Seinecke: And what’s the state of quantum physics now? Where are we at?

Dr. Pascal Macha: Quantum physics is in a very beautiful and exciting state, as the recent Nobel Prize in Physics shows. You see, Alfred Nobel stated that the prizes shall be only given to discoveries that “conferred the greatest benefit to mankind.” That is why it was only awarded this year, even though the prize specific works of the laureates started in the 1970s and culminated in the late 90s. Alain Aspect, John F. Clauser, and Anton Zeilinger are pioneers in the field of quantum information science, a field that promises a revolutionary new way of computation. Even though they helped establish quantum physics as one of the best proven physical models with quantum information science as a promising application, the benefits remained purely theoretical for a long time. Only during the last perhaps 10 or 20 years, real world applications started emerging, and actual, large-scale functional quantum information devices were demonstrated.

Christopher Seinecke: How come it took so long, and what is such a “quantum information device”?

Dr. Pascal Macha: Quantum mechanics itself lead to important industrial applications early on. Sometimes this is referred to as the first quantum revolution; prominent examples are the laser and nano-scale transistors that we find nowadays in our smartphones. Yet, these don’t use one of the most mystical and powerful features of quantum mechanics: Entanglement. Entanglement lies at the heart of the second quantum revolution and promises massive advantages when used for computation. It is also most sensitive to any type of disturbances, like the electrical noise generated by room-temperature electronics. Being so delicate, it took a long time to engineer systems that not only are quantum but also maintain entanglement for a significant time and thus allow us to manipulate highly complex quantum states without losing them to the noise. An example of such a device is the quantum computer Google presented in 2019, which demonstrated that entanglement can be maintained for a significant time and over a significant scale.

Christopher Seinecke: You’re talking as if quantum computers already exist?

Dr. Pascal Macha: Indeed, they do. They exist in various forms, a bit like in the early years of digital computing when different platforms competed for a place in the future. Before the transistor took that place, another platform still remembered is vacuum tubes.

Christopher Seinecke: What are the applications of quantum computers of today?

Dr. Pascal Macha: Similarly to the first-generation computers, they solve specific problems well suited to them. For a quantum computer, these can be optimization challenges like the traveling salesman problem or finding the lowest energy state for certain molecules. The latter is particularly interesting for the pharma and chemical industries. To develop new medicines or chemical processes, they employ large supercomputers that are expensive to operate.

Christopher Seinecke: And what makes the quantum computer a quantum computer and not just a supercomputer?

Dr. Pascal Macha: The unit for information processing is fundamentally different; instead of the bit – a digital zero or one – quantum computers use quantum bits.

Christopher Seinecke: What are quantum bits then?

Dr. Pascal Macha: It means that while at the end of a calculation a quantum bit yields either zero or one, during the calculation it can take any number between zero and one while at the same time – via entanglement – being connected to many other qubits.

Christopher Seinecke: What are the consequences in terms of practical applications? Why is that important?

Dr. Pascal Macha: Because this allows a quantum computer to solve problems that are exponentially difficult on a classical computer in a much faster fashion. This feature is coined “quantum advantage”. As the number of quantum bits is still limited, and thus the quantum advantage is just not yet there, the billion-dollar question lies in asking the right questions that can be answered with today’s quantum computers.

Christopher Seinecke: What are you up to in terms of quantum computing at your work in Australia?

Dr. Pascal Macha: I’m developing and integrating a quantum computer embedded in a silicon crystal – the same type of material our classical computers use. By means of so-called scanning tunneling microscopy fabrication, we can write tiny wires only few 10s of atoms wide and place islands consisting of single or few phosphorus atoms next to them. The phosphorus atoms in the silicon crystal form positive potentials that attract electrons. Using the wires, we can manipulate these and use them as quantum bits. The electrons form the fundamental building block of our platform. At this year’s annual conference of the American Physical Society, I demonstrated that we also have full control of the nuclear spins of the phosphorus atoms themselves. We can now use them as additional quantum bits for our architecture.

Christopher Seinecke: That sounds exciting. But before going to Australia, how did you use physics for INVENSITY?

Dr. Pascal Macha: My background in physics was a big part of my customer relationships – not few of the clients side held doctorates in physics themselves. For some projects, a high level of expertise in physics was essential for their successful execution. It enabled me to understand complex systems quickly and have technical deep dives early in the exploration phase. Also, INVENSITY believes – for good reason – in teams with diverse backgrounds from engineering, software, physics and beyond.

Christopher Seinecke: Could you give me an example of how you’ve used physics in an INVENSITY project?

Dr. Pascal Macha: My first project with a world leader in a very physics-related industry was to optimize the dataflow for an internal analysis tool. My domain-specific knowledge ensured that I was aware of the client’s needs and helped establish the initial trust. Our software consultants brought in the necessary know-how in software architecture and code refactoring and convinced the client of our expertise and ability to deliver. Together with my colleagues from the Center of Excellence Analytics & Sensorics, we started working directly on physics-related topics, for example, developing new analysis functions for their measurement data.

On another very practical occasion – we helped to develop an automotive prototype of a camera substituting a side mirror presented at the CES (Consumer Technology Show) at Las Vegas that year – a feature stopped working last minute, as it happens with prototypes. Luckily, I was close by and could get it fixed on short notice, just before it was packed up for the transfer to the show.

Christopher Seinecke: And how does your experience working at INVENSITY help you in the work that you’re doing now?

Dr. Pascal Macha: Oh, that’s an excellent question. Through my projects, I immersed myself in the processes that make our highly complex automotive industry possible and the systems engineering that makes airplanes so reliable. Furthermore, INVENSITY invests considerably in the professional development of its consultants and offers an incredible network of experts. Now, I get to employ these skills to lift a great transformational technology from its research phase towards an actual functional product.

Christopher Seinecke: Thank you for sharing your insights and your time.

Dr. Pascal Macha: My pleasure.

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