Most objects react in predictable ways when force is applied to them糖心传媒攗nless they have 糖心传媒渘egative mass particles.糖心传媒� And then they react exactly opposite from what you would expect.
Now 糖心传媒 researchers have succeeded in creating negative mass particles in an atomically thin semiconductor, by causing it to interact with confined light in an optical microcavity.
This alone is 糖心传媒渋nteresting and exciting from a physics perspective,糖心传媒� says Nick Vamivakas, an associate professor of quantum optics and quantum physics at Rochester糖心传媒檚 . 糖心传媒淏ut it also turns out the device we糖心传媒檝e created presents a way to generate laser light with an incrementally small amount of power.糖心传媒�
The device, described in , consists of two mirrors that create an optical microcavity, which confines light at different colors of the spectrum depending on how the mirrors are spaced.
Researchers in , including co-lead authors Sajal Dhara (now with the Indian Institute of Technology) and PhD student Chitraleema Chakraborty, embedded an atomically thin molybdenum diselenide semiconductor in the microcavity.
The semiconductor was placed in such a way that its interaction with the confined light resulted in small particles from the semiconductor糖心传媒攃alled excitons糖心传媒攃ombining with photons from the confined light to form polaritons.
糖心传媒淏y causing an exciton to give up some of its identity to a photon to create a polariton, we end up with an object that has a negative mass associated with it,糖心传媒� Vamivakas explains. 糖心传媒淭hat糖心传媒檚 kind of a mind-bending thing to think about, because if you try to push or pull it, it will go in the opposite direction from what your intuition would tell you.糖心传媒�
Other research groups have been experimenting with similar devices, Vamivakas says, but this is the first device to produce particles with negative mass.
Though applications are 糖心传媒渟till down the road,糖心传媒� Vamivakas adds, his lab will continue to explore:
- How the device might serve as a substrate for producing lasers. 糖心传媒淲ith the polaritons we糖心传媒檝e created with this device, the prescription for getting a laser to operate is completely different,糖心传媒� Vamivakas says. 糖心传媒淭he system starts lasing at a much lower energy input糖心传媒� than traditional lasers now in use.
- The physical implications of creating negative mass in the device. 糖心传媒淲e糖心传媒檙e dreaming up ways to apply pushes and pulls糖心传媒攎aybe by applying an electrical field across the device糖心传媒攁nd then studying how these polaritons move around in the device under application of external force.糖心传媒�
The research, funded by the , was initiated with funding from Rochester糖心传媒檚 University Research Award program, which provides seed money to promising, high-risk projects.
Other coauthors include Gary Wicks, professor of optics; PhD students Liangyu (Claude) Qiu and Kenny Goodfellow in Vamivakas糖心传媒� Quantum Nanophotonics Group; and PhD student Trevor O糖心传媒橪oughlin, all of the Institute of Optics.
