• Wed. Nov 22nd, 2023

    Critical Thought

    Critical thoughts on quantum technologies

    The Cutting-Edge Exploration of Time: Unveiling the Microscopic World with Attosecond Pulses

    ByThemba Hadebe

    Nov 13, 2023
    The Cutting-Edge Exploration of Time: Unveiling the Microscopic World with Attosecond Pulses

    Scientists have always been fascinated by the mysteries of time, and now, a groundbreaking discovery in physics has allowed us to catch a glimpse into the subatomic world’s unimaginably fast particles. Anne L’Huillier, Pierre Agostini, and Ferenc Krausz have been honored with the 2023 Nobel Prize in Physics for their groundbreaking work in developing the ability to illuminate reality on nearly inconceivably brief timescales.

    In the span of a few decades, these innovative physicists have revolutionized the field by creating laser pulses that last mere attoseconds, billions of billions of times shorter than a second. With this technology, the world around us slows down when viewed in these short bursts of light. The flutter of a hummingbird’s wings becomes an eternal dance, and even the frenetic motion of atoms appears sluggish. On the attosecond timescale, electrons are directly observable as they move swiftly through atoms, jumping from one place to another.

    The ability to generate attosecond pulses of light has not only opened the door to understanding the elusive world of electrons but also holds immense potential for various applications. Scientists are now exploring “attochemistry,” a groundbreaking field that involves manipulating individual electrons using light. By targeting semiconductors with attosecond laser pulses, researchers have observed near-instantaneous transitions from electrically non-conductive to conductive states. This breakthrough may lead to the development of ultrafast electronic devices with unparalleled speed and efficiency.

    Furthermore, Ferenc Krausz, one of this year’s Nobel laureates, is taking attosecond technology even further by harnessing its power to detect subtle changes in blood cells. This advancement could potentially assist in the early detection of cancer, allowing for faster and more effective medical interventions.

    The concept of an attosecond may seem abstract, but it plays a crucial role in untangling the mysteries of the microscopic world. One attosecond is defined as one-quintillionth of a second, or 0.000000000000000001 seconds. To put it into perspective, more attoseconds pass within a second than there have been seconds elapsed since the birth of the universe.

    Traditionally, we measure time in days, months, and years to comprehend the movements of planets, or in seconds and hundredths of a second to gauge human actions. However, as we delve deeper into the submicroscopic realm, the speed at which objects move increases exponentially. To study the instantaneous movements of electrons, scientists need a stopwatch with far finer tick marks than seconds – they need attoseconds.

    Back in 1925, Werner Heisenberg, a pioneer of quantum mechanics, postulated that the time it takes for an electron to orbit a hydrogen atom is unobservable. While this may hold true in a literal sense, Heisenberg underestimated the resourcefulness of 20th-century physicists like L’Huillier, Agostini, and Krausz. They realized that an electron’s probability of being observed changes from moment to moment, from attosecond to attosecond. Armed with the ability to create attosecond laser pulses, scientists can now directly study various electron behaviors as they evolve over time.

    But how do physicists produce attosecond pulses? In the 1980s, Ahmed Zewail successfully made lasers emit pulses lasting a few femtoseconds (thousands of attoseconds), earning him the 1999 Nobel Prize in Chemistry. However, the quest for an even faster camera seemed insurmountable. That is until Anne L’Huillier and her colleagues made a groundbreaking discovery in 1987. By shining light on specific gases, they observed the atoms becoming excited and emitting additional colors of light that oscillated many times faster than the original laser – an effect known as “overtones.”

    The researchers used quantum mechanics to predict the different intensities of these overtones and calculated how atoms would emit beams of “extreme ultraviolet” light when illuminated by a slowly oscillating infrared laser. By overlaying these overtones, they created a new wave with attosecond-scale peaks. This process of orchestrating atoms to produce finely tuned waves is analogous to an orchestra playing music.

    Over the years, scientists refined this technique and succeeded in generating attosecond pulses in the laboratory. Pierre Agostini developed the Rabbit technique, which involved generating a continuous stream of laser pulses, each lasting 250 attoseconds. Simultaneously, Ferenc Krausz’s team used the streaking method, producing and studying individual bursts of laser pulses lasting 650 attoseconds. Not to be outdone, Anne L’Huillier and her colleagues achieved an astonishing feat in 2003, creating a laser pulse lasting a mere 170 attoseconds, surpassing previous records.

    Attosecond pulses have opened up a world of new possibilities for physicists. These pulses allow scientists to investigate any phenomena that change over dozens to hundreds of attoseconds. The initial application of this technology was to observe and understand the behavior of electrons, something previously thought to be impossible. Albert Einstein’s pioneering work on the photoelectric effect in 1905 laid the foundation for our understanding of quantum mechanics, which has now been propelled to new heights with attosecond research.

    In conclusion, the breakthroughs made by L’Huillier, Agostini, Krausz, and countless other researchers are providing humanity with unprecedented access to the previously imperceptible realms of space and time. Attosecond pulses have not only shed light on the mysterious dance of electrons but also hold the key to revolutionary advancements in technology, medicine, and beyond. As we continue to explore and harness the incredible potential of attosecond pulses, the boundaries of our knowledge and capabilities are expanding, unveiling a world that was once unimaginable.


    Q: How long is an attosecond?

    An attosecond is equal to one-quintillionth of a second, or 0.000000000000000001 seconds.

    Q: What can scientists observe with attosecond pulses?

    Attosecond pulses enable scientists to study phenomena that change over incredibly brief timescales, such as the behavior of electrons.

    Q: How do physicists produce attosecond pulses?

    Physicists use sophisticated techniques involving lasers and the manipulation of atoms to create attosecond pulses of light.

    – For more information on attoseconds, visit ‘www.nobelprize.org/laureate/2023-physics’