Photonic molecule: A small step towards quantum computer
It would have been so amazing if we could have capture light photons in a container in the day time and use them at night for illumination, electricity, heating, etc. Wait for a minute, the idea is amazing, but isn't it a fantasy?
Hmm, surprisingly, scientists have reached a step ahead to make the fantasy come true.
The complexity and the vastness of the behavior of light are well-known, and which have even been acknowledged by the great scientist Einstein. One of the most interesting properties of light is its wave-particle duality. However, if we consider light as a particle, it consists of mass-less photons and these photons never interact with each other. For example, when two laser beams cross each other the direction and characteristic of the lights never change. However recently, Prof. Mikhael Lukin from Harvard University and Prof. Vladan Vuletić from Massachusetts Institute of Technology (MIT) have demonstrated the bond formation of two photons as if they behave like a particle with masses. They have shown that when light photons pass through a super-cooled medium (Bose-Einstein condensate) of atoms, the speed of light can be reduced to zero. When the temperature of the medium restricted few nano-Kelvin, photons can behave like particles having masses and interact with each other to make bond like a molecule.
Although theoretical evidence of the photonic molecules has been described for quite a while, however, due to the technical challenges, until their effort, it was not observed. They have confirmed the bonding of the two photonic molecules by measuring the time interval between the detection of the first and second photons coming out from the super-cooled medium. Their finding shows, instead of a finite time interval between the two photons, they emerge together from the Bose-Einstein condensate. They have termed their finding as a new state of matter. Interestingly, they have shown that the polarizations of these photons change and entangled with each other in the medium when they formed a photonic molecule.
Hmm, surprisingly, scientists have reached a step ahead to make the fantasy come true.
The complexity and the vastness of the behavior of light are well-known, and which have even been acknowledged by the great scientist Einstein. One of the most interesting properties of light is its wave-particle duality. However, if we consider light as a particle, it consists of mass-less photons and these photons never interact with each other. For example, when two laser beams cross each other the direction and characteristic of the lights never change. However recently, Prof. Mikhael Lukin from Harvard University and Prof. Vladan Vuletić from Massachusetts Institute of Technology (MIT) have demonstrated the bond formation of two photons as if they behave like a particle with masses. They have shown that when light photons pass through a super-cooled medium (Bose-Einstein condensate) of atoms, the speed of light can be reduced to zero. When the temperature of the medium restricted few nano-Kelvin, photons can behave like particles having masses and interact with each other to make bond like a molecule.
Although theoretical evidence of the photonic molecules has been described for quite a while, however, due to the technical challenges, until their effort, it was not observed. They have confirmed the bonding of the two photonic molecules by measuring the time interval between the detection of the first and second photons coming out from the super-cooled medium. Their finding shows, instead of a finite time interval between the two photons, they emerge together from the Bose-Einstein condensate. They have termed their finding as a new state of matter. Interestingly, they have shown that the polarizations of these photons change and entangled with each other in the medium when they formed a photonic molecule.
Even though it seems science fiction, but in future scientists may create material or container loaded with high-density photonic molecules with adaptable releasing capabilities. For example, condensing or collecting sunlight photon in the daytime and can be used for required applications. Moreover, scientists have been already aware of the application of these photonic molecules to build the quantum computer for faster and complex calculations.
The basic blocks of any computing devices are its logic gates, and it is only possible to make the logic gate when the flow of input information interacts with each other to give an output. In the case of the quantum computer too, the same condition applies to make logic gates. Although photons are one of the best means to convey quantum information, i.e. quantum bits (qubits), however, normally these photons do not interact with each other. This non-interactive behavior of the photon restricts scientist to use them for making quantum photonic logic gates. Therefore, the recent discovery of the photonic molecule opens up a new window which shows evidence of the capability of photons to interact with each other. Hence, it promises a logical step toward the realization of the quantum information processing photonic gate, i.e. quantum computer. Even though the discovery shows a promising advance towards quantum computing, huge challenges are still there before making such quantum logic gates in practice.
