Obstacles do not affect you where the laws of quantum mechanics rule. You can say that the walls are for success and only your exit tunnel, the macroscopic world is full of walls, boxes, and barriers that keep things confined but if you are small enough.
The walls within which they are enclosed, this is known as quantum tunneling. It’s a property that has fascinated – and amazed – physicists for decades. There has been a thorny question as to how long it takes for the particles to cross the “potential barrier.” Theoretically, it was suggested that the obstacle could be overcome faster than light without violating the laws of physics and that even particles could do it instantly.
To answer this question, researchers from the University of Toronto have created a clever setup. They measured how long it took for the rubidium atom in the Bose-Einstein condensate to cross the 1.3-micrometer-thick optical barrier for the first time. They saw that it took them 0.6 milliseconds, as reported in Nature.
“Knowing this can help us understand many more related processes where a system can end up in more than one final state, which is ubiquitous in quantum theory.” Senior author Professor Aephraim Steinberg told IFLScience, “We’ve known about tunneling for almost a century and use it in some of the fastest electronics, magnetic instruments of the highest accuracy, superconducting quizzes, etc. – it’s a disgrace that the process has taken us so long to realize.” “In general, the context here is not so much about tunneling as it is about trying to figure out how much quantum mechanics allows us to speculate about the past,” he said.
Individual atoms begin to behave in such a way that quantum mechanical properties become macroscopically obvious. Rubidium atoms can also be imagined as tiny magnetic spinning tops, so an external magnetic field rotates them. The Bose-Einstein condensate is often referred to as the fifth state of matter. Particles, often atoms are cooled very close to absolute zero in temperature.
The team created a local magnetic field in the barrier. Atoms begin to rotate as they pass through it, and stop as soon as they come out. The team used the atomic amount of rotation or spin accuracy as a stopwatch to measure the time it takes to cross this “forbidden” region, which they expressed as 0.6 milliseconds. It also confirmed a strange result that showed particles that reached the barrier with less energy and faster.
Professor Steinberg told IFLScience, “We’ve found a limited amount of time consistent with the theory … and the strange result is that we’re starting to make sure that particles with low energy barriers actually move faster than particles with more energy.”
“Since quantum mechanics cannot specify them individually, we can probably come closer, more importantly, the techniques we’ve developed have paved the way for testing more detailed questions. It’s not just how much time the particle spends in the barrier area, exactly where that time is spent, how the transmitted and reflected particles behave differently, and indeed, the particle time. A kind of ‘conditional probability distribution’ for what the function is doing if you know where it is going in the end: not a trajectory.”
They are already improving this experimental setup, as well as ways to further investigate quantum tunneling to understand in more detail what happens to the obstruction from a particle perspective. This is an important milestone in the field of research, but it is far from the end for the team.
