Entangled Diamonds
December 4, 2011
This week saw yet another interesting scientific result from Canadian physicists. Specifically, a team in Ontario has announced that they have detected quantum entanglement in a macroscopic system.
Since the birth of quantum mechanics over a century, it has been a puzzle due to its very odd but proven properties. Among these is the principle of quantum entanglement, in which two spatially separate objects affect each other without communicating in any ordinary way.
The standard example of this is using particles or atoms that have either a spin or a polarization (in the case of photons). Two such particles are kept together and allowed to entangle with each other. They are then separated by a relatively large distance (although it may only be a few centimeters or meters in the lab) and then experiments are performed on one of the pair. For example, the polarization of one of two photons might be measured and altered.
And in a result that shocked the physics community, its partner demonstrates similar changes to its polarization!
(Of course some people immediately assume that this violates Einstein's theory of relativity and causality, because it involves instantaneous communication and faster than light travel. But in actuality the changes to the quantum system have a random element to them, which is too complicated to explain properly here, and as such no usable signal can be transmitted in this way)
Until now, such phenomena have only been observed in experiments using single atoms, particles or light, but have never been observed on the larger scale of our everyday experiences. (You cannot brew coffee at home and have your mug at work fill up.)
However this team of physicists has claimed that by focusing laser light on a tiny diamond chip (less than 0.5mm) they were able to alter the properties of an entangled diamond chip a few meters away. If there result withstands scrutiny, it will indeed be a breakthrough in quantum mechanics experiments.
Of course as always, this is just the initial report and may still be disproven with other experiments. Quantum mechanics is based on statistics and random chance, and with such things false positives are always a risk. But for now, it looks like an interesting result and one that will certainly be studied in more detail in the coming months.
Since the birth of quantum mechanics over a century, it has been a puzzle due to its very odd but proven properties. Among these is the principle of quantum entanglement, in which two spatially separate objects affect each other without communicating in any ordinary way.
The standard example of this is using particles or atoms that have either a spin or a polarization (in the case of photons). Two such particles are kept together and allowed to entangle with each other. They are then separated by a relatively large distance (although it may only be a few centimeters or meters in the lab) and then experiments are performed on one of the pair. For example, the polarization of one of two photons might be measured and altered.
And in a result that shocked the physics community, its partner demonstrates similar changes to its polarization!
(Of course some people immediately assume that this violates Einstein's theory of relativity and causality, because it involves instantaneous communication and faster than light travel. But in actuality the changes to the quantum system have a random element to them, which is too complicated to explain properly here, and as such no usable signal can be transmitted in this way)
Until now, such phenomena have only been observed in experiments using single atoms, particles or light, but have never been observed on the larger scale of our everyday experiences. (You cannot brew coffee at home and have your mug at work fill up.)
However this team of physicists has claimed that by focusing laser light on a tiny diamond chip (less than 0.5mm) they were able to alter the properties of an entangled diamond chip a few meters away. If there result withstands scrutiny, it will indeed be a breakthrough in quantum mechanics experiments.
Of course as always, this is just the initial report and may still be disproven with other experiments. Quantum mechanics is based on statistics and random chance, and with such things false positives are always a risk. But for now, it looks like an interesting result and one that will certainly be studied in more detail in the coming months.
Posted In : News
I am a physicist recently graduated from the University of Victoria, with a doctorate in theoretical physics. I also have training in mathematics, engineering and computer programming.