Researchers at Stevens Institute of Technology have proposed a novel method to control quantum systems using a sequence of twelve weak laser pulses instead of a single intense beam, avoiding disruptive multiphoton processes that hinder quantum computing and precision measurements, as detailed in a study published on September 10, 2026.
Quantum technologies rely on manipulating the energy states of atoms and molecules using laser pulses. Yet the intense fields required for this control often trigger unwanted disruptions known as multiphoton processes, making the behavior of the targeted system difficult to predict.
Researchers at Stevens Institute of Technology and their collaborators have proposed a theoretical solution to this hurdle by digitizing ultrafast adiabatic passage with a pulse train, published in the Journal of the Optical Society of America B on September 10, 2026.
Digitizing Laser Pulses to Protect Quantum Systems
When a powerful light wave reaches a quantum system, photons are absorbed by atoms and molecules, pushing those particles into higher-energy states. If the laser field is particularly intense, a particle may interact with multiple photons simultaneously. This opens additional pathways between energy states and disrupts the desired dynamics.
“By shining laser light on molecules, we can excite molecular vibrations in a controlled way and learn about molecular properties, but when very strong laser fields are used for precise quantum control, they can also trigger unwanted multiphoton processes allowing the molecule to access many different states and pathways, making its behavior much more difficult to predict and control.”
Svetlana Malinovskaya, professor at Charles V. Schaefer, Jr. School of Engineering and Science at Stevens Institute of Technology
Unpredictability poses a significant obstacle when scientists require exact control for applications where every photon counts, such as quantum computing and quantum sensing. To eliminate these unwanted interactions, researchers calculated that a series of twelve short, low-intensity laser pulses could produce the same net effect as one long, intense pulse.
“Instead of using one very strong laser pulse, we suggest mimicking its effects with a carefully programmed sequence—or train—of weak pulses. Each pulse carries much less energy, but its timing, intensity, frequency and phase are precisely calculated and controlled.”
Svetlana Malinovskaya, professor at Charles V. Schaefer, Jr. School of Engineering and Science at Stevens Institute of Technology
The calculations show that this train of pulses achieves a gradual transfer of a quantum system from one state to another without pushing particles into difficult-to-control states. While the study is currently theoretical, the research team outlines all necessary calculations to prepare for laboratory testing, which will open a new way to precisely control quantum systems with weaker laser fields.
Broader Implications for Molecular Physics, Biology, and Medicine
Beyond quantum computing, sensors, and simulators, this methodology holds practical applications across molecular physics and spectroscopy, where high-intensity lasers often interfere with measurements. In biology and medicine, where laser imaging is used for diagnosing diseases, reducing pulse intensity can minimize damage to sensitive cells and tissues.
The Stevens development arrives alongside separate quantum explorations at the institution. In a study published on April 20, 2026, in Physical Review Letters, researchers explored the quantum aspects of proper time in optical ion clocks in collaboration with Colorado State University and the National Institute of Standards and Technology. That theoretical work demonstrated how atomic clock technology might soon detect quantum superpositions in the flow of time itself.
Path Forward for Experimental Demonstrations
Both the laser pulse optimization and the ion clock investigations underscore how rapidly improving quantum tools are pushing past traditional boundaries.
