PPPL's Mark Martirez screens diamond qubit defects by simulating them as small molecules
Mark Martirez, a staff research scientist at the Princeton Plasma Physics Laboratory, simulates diamond qubit defects as isolated clusters of 16 to 30 atoms. Simulation turned up boron- and oxygen-based defects that could make useful qubits. They are candidates until someone grows and measures them.
The Scientist · Science desk
What happened
- The work was published in ACS Central Science, according to phys.org's report on it.
- Treating the cluster as a molecule lets Martirez use accurate tools that chemists have applied to simple compounds for decades.
- With the approach, the team simulated how qubits respond to light and microwave pulses far faster than before, the account says.
- Diamond-based materials work at room temperature, while most other candidate materials hold a stable quantum state only when chilled to extreme temperatures.
Why it matters
- constraint The defects are described as ones that could make useful qubits, so fabrication and optical read-out remain the test of the simulated predictions.
- capability Distinct emission colors open a design option for a single device. "One could imagine, then, combining different qubits of different responses, so you can basically probe one qubit but not the other," Martirez said.
- precedent Martirez argues diamond qubits can be designed the way a chemist designs a new medication. That brings chemistry's decades-old calculation tools to a problem physicists often treat as their own.
The cost claim is Martirez's own. "Because we're treating the qubits as molecules, the cost of calculating these defects is equivalent to the cost of just modeling a simple molecule," he said [10]. He added that the method "really opened the floodgates" in terms of how qubits can be assessed [11]. The cluster is a reasonable thing to keep, since the atoms closest to a defect form the qubit [9].
Calculation cost is the only thing that claim measures. How well 16 to 30 atoms stand in for a whole crystal is a separate question. The phys.org account says the simulations ran far faster than before [12], but it does not give a speed-up factor or a laboratory measurement of the boron and oxygen defects.
The natural control is the nitrogen-vacancy defect. Most quantum diamond research has focused on it, and a laser makes it emit red light when it is in a particular quantum state [6]. We would want to see the cluster method reproduce that known behavior before leaning on the predicted blue emission of the oxygen-based defects and the ultraviolet emission of the boron-based ones [7]. If it does, we think a cluster screen is a sound way to rank candidates, and the boron and oxygen defects are worth growing.
Martirez's longer-range case runs back to chemistry. He said a practical multi-qubit system would vastly improve the accuracy of quantum chemistry calculations: "We could describe larger molecules, biomolecules, proteins and everything like that in a more accurate way, and that could improve all the chemical-adjacent industries, such as pharmaceutical science and materials science." [14]
What to watch
- Laboratory emission spectra from grown boron- and oxygen-based diamond defects, set against the simulated ultraviolet and blue colors.
- A published comparison of the cluster method with a conventional calculation on the nitrogen-vacancy defect, giving both a speed-up factor and an accuracy check.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence40
- Adoption
- Insufficient
- Hype gap+35
- Incentives60
- Confidence50
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
A researcher at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) developed a faster way of finding the best diamond-based materials for quantum computers.
- [2]
The research was published in the journal ACS Central Science.
- [3]
Mark Martirez, a staff research scientist at PPPL, carves out a small cluster of just 16 to 30 atoms around the defect and treats that cluster as an isolated molecule.
- [4]
Treating the cluster as an isolated molecule lets Martirez apply highly accurate tools that chemists have used for decades to study simple compounds.
- [5]
The simulations led the researchers to discover new boron- and oxygen-based defects that could make useful qubits.
- [6]
Most quantum diamond research has focused on the nitrogen-vacancy defect, in which one carbon atom is replaced by nitrogen and a nearby spot is empty; when scientists shine a laser on this qubit, it emits red light if it is in a particular quantum state.
- [7]
The oxygen-based defects Martirez is studying shine blue, while the boron-based defects emit ultraviolet light.
- [8]
Most materials being considered for quantum technology can only hold a stable quantum state when chilled to extreme temperatures, while diamond-based materials are functional at room temperature.
- [9]
Pure diamond won't work as a qubit; defects are essential for storing and processing information, and the clusters of atoms closest to a defect form the qubit.
- [10]
"Because we're treating the qubits as molecules, the cost of calculating these defects is equivalent to the cost of just modeling a simple molecule," Martirez said.
- [11]
Martirez said of the method: "This method really opened the floodgates" in terms of how qubits can be assessed.
- [12]
Using the new approach, the researchers were able to simulate how qubits would respond to light and microwave pulses far faster than ever before.
- [13]
Scientists often treat diamond-based qubits as a physics problem; the new research shows they can also be understood through chemistry, enabling scientists to design and build qubits the way a chemist designs custom molecules, such as a new medication, for a specific purpose.
- [14]
Martirez said a practical multi-qubit system would vastly improve the accuracy of quantum chemistry calculations: "We could describe larger molecules, biomolecules, proteins and everything like that in a more accurate way, and that could improve all the chemical-adjacent industries, such as pharmaceutical science and materials science."
- [15]
"One could imagine, then, combining different qubits of different responses, so you can basically probe one qubit but not the other," Martirez said.
Sources
1 independent publisher whose own reporting we read for this story.
- phys.orgFaster molecular simulations identify promising diamond defects for quantum computers and sensors
1 article · October 13, 2026
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