The hyperfine states serve as a two-level system that permits each ion to function as a quantum information bit, or “qubit,” as it exists in some combination of both states at the same time. In part one, the ions are placed in a superposition of two hyperfine states – tiny energy differences within a single excitation level of an atom that result from electrons’ interaction with the nucleus.
The researchers entangled the ions in a two-part process in which both parts occur simultaneously, generated by the laser pulses. As a result, there is intense global interest in finding dependable, high-speed entanglement schemes. The goal of the experiment was to entangle these two ions – that is, to place them in a condition in which the quantum state of one is inextricably connected to the state of the other – using light from a single high-speed pulsed laser.Įntanglement is the method that will likely be used for transferring quantum information from place to place in any future quantum computer or information-processing system. The team, led by JQI Fellow Christopher Monroe, began by preparing two ytterbium ions, spaced about five micrometers apart in an electrical trap, in identical minimal-energy ground states. No faster than light communication is required.For the first time, scientists have employed a powerful technique of laser physics – the “optical frequency comb” – to entangle two trapped atoms.* This form of control is a promising candidate for use as a logic gate for quantum computing and information-processing, and offers substantial operational advantages over other methods of laser-generated entanglement. When you observe a particular state for a particular partite, then it simply means that you are restricting yourself on one of the worlds and then the state of all the other partites, regardless of how far away they are, are fixed to be the states they would have on that particular world. Quantum entanglement implies different worlds, each having particular states associated with the different partites that are entangled. Using this interpretation, one can quickly see that no quantum entanglement scenario can ever produce faster than light communication. One interpretation that is quite simple to use for this purpose is the many world interpretation, because it does not include collapse.
Since no one has so far figured out how to observe physical differences based on these interpretations, all these interpretations will produce exactly the same physical results. It doesn't have to be one that you believe is true.
Just pick one particular interpretation that is fairly simply to understand and work it out in terms of that interpretation. However, there is a bit of a trick that one can use to help one to figure out how particular situations in quantum mechanics would work. Part of the problem is that the interpretation is, well, open to interpretation. It is often said to be difficult to understand how quantum mechanics works and often some famous physicists are quoted to say that nobody understands quantum mechanics.
It is a fundamental aspect of quantum entanglement. The reason why one cannot do faster than light communication using quantum entanglement is not because we have not been clever enough to come up with a scheme that would work.