A Quantum Leap Forward: How Tiny Particles Can Bring Us Exciting New Tech

Credit: B. Hayes/NIST

From the development of lasers and transistors to medical imaging and GPS, quantum science underpins the technologies that drive modern society. As a fundamental theory in physics, quantum explains the behavior of the universe at the atomic scale. This behavior is quite different from our normal experiences with the world.

To celebrate the International Year of Quantum Science and Technology, Taking Measure spoke with physicist Corey Stambaugh, the chief of staff of NIST Physical Measurement Laboratory, who helps lead our quantum activities including public outreach efforts, to learn more about quantum and how it may shape technology in the coming years.

Why are we celebrating the International Year of Quantum this year?

Quantum builds on 20th-century technologies, such as lasers and the atomic clocks that are the beating heart of GPS. Now, quantum is opening up new possibilities with the development of quantum computers and related technologies. The purpose of the International Year of Quantum is to raise awareness of the importance of quantum in our daily lives and the potential impact it will have in the decades ahead. It’s especially exciting that this year coincides with the 100th anniversary of quantum mechanics. Of course, we also want to excite the next generation of researchers, innovators and users who will be developing and deploying these new technologies.  

One of the aspects of quantum I love the most is that quantum so often goes against our intuition. There’s a lot of critical thinking involved in this work. Quantum behavior is different from what we’re used to observing. That means you have to do the test or the experiment. You may have a certain instinct about how something should work, but the experiments will often tell you something different. This tension played out over a hundred years ago, as scientists struggled with whether light was a particle or a wave. (It’s both.) The answer helped lead to the birth of quantum.

Why is quantum important?

Researchers are using quantum science to develop quantum computers that can do tasks classical computers simply can’t do (or can’t do efficiently) today, such as designing new drugs or developing new materials.

Using quantum mechanics in computing and communication is a field known as quantum information science. Quantum information science is now letting us see the world in new ways, similar to opening up the aperture and improving the resolution on a camera.

For example, we are using quantum to deploy devices that can measure brain waves. This technique, known as magnetoencephalography (MEG), is used to understand how the brain works and to precisely identify areas of the brain for surgery. Early implementations took up a whole room and were not easy to use with infants. Today, quantum is enabling more compact approaches to MEG. Small devices that measure magnetic fields, known as chip-scale atomic magnetometers, are being used to make more portable designs, as well as more compact instruments that can be used on patients of all ages.

How do quantum behaviors work?

Two of the most notable behaviors in the quantum realm are superposition and entanglement.

When you flip a coin, you know you’ll get a definite result — either heads or tails. But that is thinking about the world as we see it or a “classical” approach. You have to zoom into the quantum realm to see superposition in action. You can still think of it like flipping coins but with a twist. Superposition allows a particle to be in a state of heads and tails at the same time. It’s only once you make a measurement that your particle becomes either heads or tails. (This may sound familiar if you have heard of Schrödinger’s famous cat.)

Entanglement describes a link between two or more particles so strong that the measurement result of one particle is directly correlated to the other particle. This is the case even if they are on opposite sides of the galaxy. For example, consider flipping two coins that are not entangled. The outcome of each coin (heads or tails) is completely independent of the other. If the first coin lands on “heads,” the second still has a 50/50 chance of landing on either “heads” or “tails.” But if they are entangled in the right way, looking at the result of the first flipped coin tells you exactly the outcome of the other. That is, if the first lands on heads, the other must land on tails.

While the effects of measuring entangled particles are instantaneous, quantum physics sadly does not allow us to communicate faster than the speed of light. That’s because there’s no way to transmit information about the measurement results without a text message or other means of communication. So, we will still need classical communication; quantum can’t do everything better.

What are some misconceptions people have about quantum?

People often describe quantum as “magical” or “mysterious.” I certainly understand why, since it’s so different from our everyday experience. But I’ve tried to move away from words like that. The fact is that quantum is one of the most tested and successful theories in science. Our ability to use quantum to develop new technologies demonstrates that we can and do understand it. Of course, there are still questions, but that is how science works.

When I was young, “It's not rocket science” was a way of saying something was easy to understand. The implication, of course, was that rocket science was difficult. My biggest fear is that the phrase is updated to “It’s not quantum science.” It turns out that rocket science can be adapted to all levels of understanding, including elementary and middle school science projects. I want the same for quantum — that we can adapt it to students as early as middle school or high school.

I spent several years working at the White House Office of Science and Technology Policy in the National Quantum Coordination Office. During that time, we developed a strategy for quantum workforce education. Early on, we worked with about 30 educators and scientists to develop core quantum concepts. One of the concerns we heard was that quantum was too hard for the average student to grasp. But it doesn’t have to be this way.

So much of what’s happening in quantum is already being taught in school. If you’re learning math, chemistry or computer science, for example, you’re already learning a lot of the fundamental building blocks of quantum science, such as probability or the structure of atoms. Our hope is that schools can start introducing quantum concepts earlier on, so students will be more comfortable with it by the time they get to college. Already, we are seeing quantum concepts being added to state standards, teachers taking professional development to learn these concepts, and students having more opportunities to learn about quantum in the classroom and online.

Why is NIST home to so much cutting-edge quantum research?

Quantum sets fundamental limits on measurement. So NIST, as the national metrology institute for the U.S., has a critical role in advancing quantum science. If we’re going to be the very best in measurement science, if we are going to push the limits of what we can measure, we must be the best at quantum.

For example, NIST’s decades-long expertise in quantum enabled us to contribute to a much more accurate and reliable standard for the kilogram as part of the broader redefinition of the metric units (known as the SI) in 2018. Previously, the standard kilogram was a physical object whose mass could change over time. Now, we define it by a fundamental constant, known as Planck’s constant.

Credit: B. Hayes/NIST

Additionally, to build quantum computers, you have to exquisitely control quantum states, known as qubits (the quantum analog to the bit used in traditional computers). We’ve been precisely controlling and measuring the states of atoms for atomic clocks for decades, so we already have a lot of experience in this area. NIST garnered four Nobel Prizes because of our expertise.

We have led on quantum and will continue to because it’s so important to measurement science, to the future of technology and to U.S. competitiveness.

Talk about your background and how you got into this field.

To be honest, I decided to major in physics without really knowing what it meant for my future career. Of course, I had classes in quantum physics in undergraduate and graduate school. However, it wasn’t until I was a postdoctoral researcher that I really got to do quantum-related research. After I completed my postdoc, I continued working in precision measurement science (metrology), working on the redefinition and dissemination of the kilogram.

I started teaching at Montgomery College here in Maryland around that time. I did this in part because I wanted to help students know about the opportunities that I was unaware of when I first started college.

I still teach there today, in addition to my work at NIST. Some of my students go on to work in the science, technology, engineering and math (STEM) fields. Others only take one course in science and then move on to something else. I want them to learn the basics, but I really want them to gain a new appreciation for how to look at the world. This hands-on work, teaching community college students, was crucial to my later work in quantum workforce development and education.

What do you see as the future of quantum?

The United States and the world are invested in developing quantum technologies. Many people are working on this. The fact that younger researchers are now getting involved means we have new pathways for talent to flow into this area. Having so much expertise and energy directed at quantum will mean we can open new scientific frontiers as the technology develops. Generations of students have now studied computer science, and this technology has evolved rapidly. Quantum computing is poised to be the next revolution.

I’m excited to see what the next five years bring to the world of quantum. There are optimistic predictions about when large-scale quantum computers capable of solving real-world problems will become commonly available. I can’t say how accurate they are because there are still some big challenges to overcome, but I am confident we will get there.

I do know we need to keep people — particularly future quantum professionals — excited about the possibilities. If we inspire a student today, in 2025, to pursue a career in quantum, in 10 years they will be in school or on the job working toward solving problems with quantum computers. It’s an exciting time to be in this field, and I hope more will join us.