Microscope that can 'freeze time' by capturing one quintillionth of a second
A new electron microscope can effectively freeze time, taking pictures of events that last just 1 attosecond. This makes sense because the subatomic world is difficult to visualize. Not only is it incredibly small, but events happen incredibly fast there. Physicists at the University of Arizona have built the world's fastest electron microscope to capture events that last just one quintillionth of a second.
Quite often I write about the brain and consciousness, but there are processes that occur in the depths of not only neurons, but also electromagnetic impulses that activate neurons. Together with the theory of the phase state of the brain, the situation looks curious.
Shooting in a split second
A good camera with a shutter speed of milliseconds can take a sharp picture of a person running. But the fastest “cameras” in the world – transmission electron microscopes – can capture events on the scale of attoseconds. For example, they can photograph a running electron. An attosecond is one quintillionth of a second, which makes a millisecond (a thousandth of a second) an eternity. Something similar to what a person feels when they are in the REM phase of sleep, when the perception of time is distorted.
If we try to make a comparison, there are as many attoseconds in one second as there are seconds in 31.7 billion years. This is twice as long as the lifespan of our universe. Here we are faced with truly incomprehensible numbers.
Previous attempts to capture events on a quantum time scale have reached their limits 43 attosecondsAt the time, researchers called the image “the shortest controlled event ever produced by humanity.” Now, a team from the University of Alberta has gone one step further, freezing time in the format of one attosecond.
The new work builds on research by Pierre Agostini, Ferenc Krausz and Anne L'Huyère, who generated the first light pulses short enough to be measured in attoseconds. This gave the team Nobel Prize in Physics in 2023.
Construction of an attomicroscope
For the new study, the scientists developed what they call an “attomicroscope.” First, a pulse of ultraviolet light is fired at a photocathode, which releases ultrafast electrons inside the attomicroscope. Then, a laser pulse is split into two beams, and both beams are fired at the electrons moving through the microscope. One of the beams is polarized, and they arrive at slightly different times, generating a “gated” electron pulse that can visualize a sample. In this case, graphene.
Schematic of an attomicroscope. An ultraviolet laser (pink) fires an ultrafast pulse of electrons (green) inside the attomicroscope. The laser pulse is then split into two beams (orange) that hit the sample at slightly different times, firing a single attosecond electron pulse that images the sample.
Using this technology, the team was able to generate electron pulses lasting just one attosecond, allowing the ultrafast movement of electrons that are normally invisible to be observed. The researchers say the breakthrough could have applications in quantum physics, chemistry and biology.
Improving the time resolution of electron microscopes has long been expected and a focus of many research groups because scientists want to see the movement of electrons. These processes take attoseconds. But now, for the first time, we can achieve attosecond time resolution with our transmission electron microscope — and we call this “attomicroscopy.” For the first time, we can see parts of an electron in motion.
Mohammed Hassan, author of the study.
The world is big and amazing. What was just a few decades ago an element of science fiction films is now being implemented step by step into reality. More materials about strange tools for the brain, technologies and prospects – you will find in our community. Check back to keep useful content at hand.
