Engineers at UNSW have demonstrated that reshaping the quantum dots inside of a quantum computer to be like jellybeans could allow for greater breathing space in crowded circuitry.
Quantum computers are made of many complex components, with quantum dots being one of the parts. These are nanoscale crystals that can transport electrons and emit different lights when exposed to a UV light. In the context of a quantum computer, quantum dots make up qubits, which make up the data for a quantum computer while capable of moving between different states of superposition.
And now, a team of engineers at UNSW reckon jellybeans could be the perfect inspiration for quantum dot shapes by giving the dots more breathing room. If UNSW’s work in Quantum Space is ringing any bells, it’s because a team from the university smashed a huge quantum computing barrier back in February.
‘Jellybean quantum dots’, as the announcement reads, are quantum dots with elongated areas between qubit pairs to create more space for circuitry without disrupting the pair.
The jellybean shape for similar technologies isn’t a new concept, according to lead author Associate Professor Arne Laucht, but up until now it hasn’t been explored in silicon.
Now, the team has described how quantum dots shaped like jellybeans could be possible in silicon, which could lead to more efficiently spaced wiring in quantum computers to better control the qubits.
“We showed in the paper that if you only load a few electrons in that puddle of electrons that you have underneath, they break into smaller puddles. So it’s not one continuous jellybean quantum dot, it’s a smaller one here, and a bigger one in the middle and a smaller one there. We’re talking of a total of three to maybe ten electrons,” lead author of the paper Zeheng Wang said.
“It’s only when you go to larger numbers of electrons, say 15 or 20 electrons, that the jellybean becomes more continuous and homogeneous. And that’s where you have your well-defined spin and quantum states that you can use to couple qubits to another.”
The team still has more work to do, according to Laucht, and the next step is to insert qubits at each end of a jellybean quantum dot, and have the qubits talk to each other.
“It is great to see this work realised. It boosts our confidence that jellybean couplers can be utilised in silicon quantum computers, and we are excited to try implementing them with qubits next,” Laucht added.
Quantum computing is a booming space in the tech world and funding for the development of quantum systems picked up $101 million in the 2023 budget.
You can read about the jellybean research in Advanced Materials or on the UNSW website.