Single Light Pulse Can Control Quantum States in 2D Materials: IIT Bombay
Mumbai, December 14, 2025 – Scientists at the Indian Institute of Technology (IIT) Bombay have made a significant breakthrough in the field of quantum technology. They have discovered a new method to control quantum states in ultra-thin materials using a single light pulse. This advancement has the potential to revolutionize computing, leading to devices that are significantly faster and more energy-efficient than current electronic technologies.
Understanding 2D Materials
Two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides, are materials that are only one atom thick. They are thousands of times thinner than a human hair and exhibit unique electronic properties. One of the fascinating features of these materials is the ability of electrons to occupy two distinct quantum states, known as valleys. These valleys are referred to as K and K′.
The Concept of Valleytronics
The concept of valleytronics is a growing area of research that leverages these valley states as a new means of information processing. In digital computing, information is typically represented as binary values, 0 and 1. Similarly, the K and K′ valleys can be thought of as quantum equivalents of these binary states. However, controlling these valley states has proven to be a significant challenge for researchers.
Challenges in Controlling Valley States
Previously, techniques to manipulate valley states required complex laser setups, often utilizing circularly polarized light and multiple laser pulses. These methods were not only complicated but also resulted in incomplete control over the valley states, making reliable and reversible switching between them a daunting task.
A Breakthrough Discovery
The research team at IIT Bombay has demonstrated that a simpler approach is possible. In a study published in the journal Advanced Optical Materials, they revealed that a single linearly polarized laser pulse can effectively control and read the valley state of electrons. This method introduces a small, controlled skew in the laser pulse’s polarization, which is sufficient to push electrons into either the K or K′ valley.
Mechanism of Control
According to Professor Gopal Dixit from IIT Bombay, this slight asymmetry in the laser pulse allows for the manipulation of the electron’s valley state. By reversing the skew in the pulse, electrons can be switched back to the other valley, making the process fully reversible. This characteristic is crucial for the development of quantum computing, as it allows for the dynamic representation of information.
Simultaneous Control and Measurement
One of the most significant aspects of this discovery is that the same laser pulse generates a tiny electric current. This current serves as a built-in signal indicating which valley state the electrons have transitioned into. In essence, the system can be controlled and read simultaneously, eliminating the need for additional lasers or measuring devices.
Wide Applicability
The researchers found that their method is effective across a broad range of laser wavelengths and does not require precise tuning to match the material’s energy levels. This versatility enhances the practicality of the technique, making it applicable to various 2D materials and potentially paving the way for widespread adoption in quantum technologies.
Implications for Future Technologies
The ability to control quantum states with a simple and efficient method opens up new avenues for the development of quantum computers. These computers promise to perform calculations at speeds unattainable by classical computers, with significantly lower energy consumption. As the field of valleytronics continues to evolve, the research from IIT Bombay could play a pivotal role in the next generation of computing technologies.
Conclusion
The breakthrough achieved by the IIT Bombay team marks a significant step forward in the field of quantum technology. By simplifying the control of quantum states in 2D materials, they have laid the groundwork for more efficient and powerful computing solutions. As research in this area progresses, we may soon witness the emergence of quantum devices that could transform industries and daily life.
Note: This article is based on research findings published in the journal ‘Advanced Optical Materials’ and aims to provide an overview of the recent developments in valleytronics and quantum computing.
