The student news site of Thomas Jefferson High School for Science and Technology


The student news site of Thomas Jefferson High School for Science and Technology


The student news site of Thomas Jefferson High School for Science and Technology


This error message is only visible to WordPress admins

Error: No feed found.

Please go to the Instagram Feed settings page to create a feed.

Under lock & key

Four students explore quantum key distribution, the future of data encryption
Anya Raval
Gesturing towards their project, senior Alec Riso describes the mechanisms of the group’s QKD system alongside senior Karthik Thyagarajan. “This laser generates a stream of photons. We lined it up with a collimated lens, [which] focuses the laser into an optical fiber,” senior Connor Whiting said. “The optical fibers [preserve or maintain] are how you measure the polarization state of the photon, which lets us do the encryption protocol.”

“How can I help you today?”

Nearly every person across the globe has seen those words in generic font underneath Chat-GTP’s logo. Since the Artificial Intelligence (AI) model developed by OpenAI was released in late 2022, AI has taken over the scientific community. Over 2,500 companies use OpenAI, with some even developing their own models, including Google, Microsoft and Facebook.

Once the AI craze dies down, quantum computing may be the next big watershed technology.

“Right now we’re in the era of Artificial Intelligence. This is what’s driving scientific discovery. The question is, ‘What’s next?’” Quantum Information and Optics Lab director Mark Hannum said. “Quantum computing is what the next thing is. Making sure that students have an opportunity to learn about the next revolution before it happens is the reason why people should come to TJ.”

Four seniors—Katherine Jimenez, Alec Riso, Karthik Thyagarajan and Connor Whiting—are currently researching QKD, an encryption protocol, in the Quantum Information and Optics Lab.

“We’re sending a key that can be used to encrypt a message over a fiber optic cable and using a photo. Through that we should be able to make sure that we’ll send it securely so that only the two people on either end will have that key,” Jimenez said. “We can check if somebody has measured or hasn’t gotten our key.”

As a key distribution protocol, quantum key distribution (QKD) notifies an individual if their data has been breached and simultaneously encrypts data that someone could send to another.

“You generate a key, which is just a sequence of bits, and you use special quantum properties to transmit that sequence to the other end,” Thyagarajan said. ”If you were to do this classically, whoever wants to eavesdrop on your conversation can pull out the information, make a copy and send it back. That means that your information can get breached and that’s why we have a bunch of encryption protocols to prevent this from happening, like public [and] private keys.”

Success using the classical system is not guaranteed. In contrast, QKD, due to quantum properties, is almost completely secure.

“There’s something called the ‘no-cloning theorem,’ which means that you can’t make a copy of a quantum state,” Thyagarajan said. “That allows you to send something through a public channel. If somebody wants to eavesdrop on your sequence, they can’t retransmit it without you knowing that somebody looked at it. With just 100 qubits, you have odds of one over two to the 100, which is basically zero. It’s almost impossible to crack and it’s hyper-secure.”

Four seniors, Connor Whiting, Alec Riso, Karthik Thyagarajan and Katherine Jimenez from left to right, pose behind their research project in the Quantum Information and Optics Lab. “One of the issues is it requires an incredible amount of precision for fiber optics. Essentially, we’re just doing exactly what would be done in real life, but on a much larger scale,” Riso said. “One thing that gives our group a better chance of completing the project is we started early. Me and Karthik [Thyagarajan] started thinking about this last year. We knew exactly what we wanted to do and how to do it and we had a pretty good understanding of everything before we started.” (Anya Raval)
However, these quantum systems tend to face additional interference with its signal, making it difficult to introduce in the real world.

“They’re prone to lots of noise, which means that if we do want more secure implementations of quantum key distribution systems in the future, we need to figure out how to implement things in practical systems,” Thyagarajan said. “We want to work towards feasible, practical implementations of this algorithm in real life.”

Countries including Russia, China and South Korea have all, to some degree, begun to implement QKD to national security. Because of the noise quantum systems typically include, it is difficult to implement quantum key distribution on large scales.

“It’s going to be immensely difficult to set this up on large scales. It’s especially important that this kind of research happens sooner rather than later,” Thyagarajan said. “Eventually we’re going to hit a point where our current encryption protocols are not enough and quantum key distribution will be important and we are going to see a big push for practical implementation. The sooner we have the foundation to pursue that practical implementation the better.”

Beyond just national security, quantum computing is becoming more and more significant to the future of technology.

“We’re moving past that initial stage where a lot of the groundwork for quantum computers was done by physicists and engineers. Now we’re into the implementation phase. We need people who are fluent in some of the basics [and] apply it to their field to push the boundaries of what they’re interested in, not just what physicists are interested in,” Hannum said. “Science is alive. Physics is a field of now, not Newton.”

Electrodynamics: the course

Electrodynamics is a yearlong post-Advanced Placement (AP) course offered at Jefferson. It spends over one semester on quantum mechanics, over one quarter on advanced Electricity and Magnetism (E&M), and the remaining time on special relativity and Einstein’s postulates of space-time.

“It’s always been a pretty unique type of course for any high school. I don’t know of any other high school that actually teaches a course like this in quantum mechanics,” Hannum said. “It is exactly the type of course you’d come to TJ [for]. You have an opportunity to do this thing that you can’t do anywhere else.”

Jefferson introduces the concepts of quantum mechanics differently than most other university quantum mechanics courses.

“Here at TJ we do something called [a] ‘spins-first’ approach. We try to simplify the introduction of quantum mechanics by focusing on a smaller finite system, which has to do with an electron spin,” Hannum said. “It’s a much easier way for students to learn the material and get started in their understanding of quantum mechanics.”

This type of curriculum grants students a stronger foundational understanding of quantum mechanics for college and research.

“You get ahead on what you’re doing in college,” Smith said. “You get to learn this stuff when your mind is sort of first developing. It’s exciting. I think a lot of people take it because they just want to see it.”

Despite the lighter course load, Electrodynamics remains a difficult course due to the non-intuitive concepts of quantum dynamics, drastically differing from the deterministic logic behind the physics taught in AP Physics.

“The concepts are just so non-intuitive. The first time you take physics you see [it] as being very deterministic. You have some initial conditions, you have a projectile, it’s got some initial speed and some launch angle. You can always predict where it’s going to land using kinematics or other ways of understanding the system. You’re trained in that way for a whole year,” Hannum said. “Then you take Electrodynamics and Quantum Mechanics and you realize that, ‘Oh, the universe is not deterministic, it’s probabilistic.’ You have to completely retrain the way that you think about physics because of that.”

Jefferson can offer advanced courses such as Electroydnamics because of greater interest and funding, but quantum mechanics can still be taught at other high schools throughout the nation.

“I wish more high schools taught quantum mechanics or even modern physics, in general. I think it would be well received at lots of different places,” Hannum said. “There’s no reason why it only has to be a TJ other than other schools just haven’t invested in it.”

Story continues below advertisement
Leave a Comment

Comments (0)

Information about our comments policy can be found here:
All tjTODAY Picks Reader Picks Sort: Newest

Your email address will not be published. Required fields are marked *