Secret quantum clock a leap forward in 100 years of timekeeping accuracy
So much of modern life relies on GPS that some estimate that a failure would cost the global economy more than $1 billion a day - an explanation that is not too far-fetched: in the recent Russia-Ukraine war, Russia is jamming GPS satellite signals in Ukraine; in Iran, U.S. stealth drones are being hacked by spoofing their GPS coordinates; and disruption by solar flares.
Since 1993, when GPS created a constellation to provide global positioning, navigation and timing information, Russia, China and Europe have followed suit.
At its core, however, GPS is a timing system; quantum technology is leading the revolution in this technology.
To understand the relationship between timing and navigation, and how quantum technology will allow us to overcome the limitations of GPS, we need to go back a few hundred years -
Dava Sobel's book Longitudinal (Longitude) tells the story of John Harrison's mechanical clock that revolutionized maritime navigation and global trade. Just as Harrison's clocks accelerated economic growth in the 18th and 19th centuries, optical clocks are fundamentally changing industries as diverse as transportation, financial services, communications, and energy.
Essentially, building an accurate clock requires finding something that beats quickly and with a high degree of regularity and stability. harrison's H4 clock, completed in 1759, is a mechanical device that beats five times per second, keeping time within one second of error over the course of a month. Today, we are on the verge of a commercial optical clock: it "ticks" over 100 trillion times per second and is accurate to within one second over the entire age of the universe.
This astounding increase in time accuracy is arguably the most significant technological leap in human history.
Time determines the events of our daily lives. When is my next meeting? How many minutes do I have before I can catch my flight? When does the race start? We measure the timing of events in hours, minutes and seconds. If it were an NBA steal, maybe we would be accurate to a tenth of a second. Many of the technologies we currently rely on utilize more precise time measurements.
For example, we take GPS for granted. Just pull up an app on your phone and the user knows where you are anywhere on the planet: even to within a few meters. gps is essentially a timekeeping system: each gps satellite has four atomic clocks on board that transmit an integrated time signal. gps receivers (like the one on our phones) use small differences in the time signals from multiple satellites (combined with their local time reference) to triangulate your location.
The international definition of a "second" is based on the frequency of the quantum transition of the ground state of the cesium-133 atom: more than 9 billion "ticks" per second. The first cesium clock was built in 1955, and this frequency has been the global standard for timekeeping ever since.
Some quick math shows how this "tick" rate determines the positioning accuracy of GPS, whose radio signals travel at the speed of light, which can travel about 30 centimeters in a billionth of a second. Therefore, in the time it takes a cesium clock to "tick", light travels approximately 3 centimeters; although the reality is more subtle, this gives the maximum positioning accuracy of GPS.
At this point, high-precision, deployable quantum clocks would make possible a reliable and stable source of time, independent of GPS, enabling accurate navigation even when GPS is unavailable (e.g., in space, under the sea, or in mountains), blocked, or disputed.
Currently, quantum clocks are the most accurate timekeeping tools in the world, providing a powerful guarantee for astronomy, navigation, and space navigation.
The main working principle of quantum clocks. There are many different types of atomic clocks, but they usually share the same basic working principle: they include a transmitting shaker, a wave counting detector and an atomic control unit for regulating the oscillator when it is out of sync. The laser frequency is much higher than the microwave frequency, and the biggest difference is that the microwave oscillator is replaced by a super-stable laser. The laser oscillates at a frequency too fast to be read electrically, so an optical frequency comb is required. Source: ICV TAnk
With the construction of 5G networks and the advancement of artificial intelligence and the information society, the transmitted big data is putting higher demands on the time synchronization of various smart mobile terminals. To achieve this goal, we need a timing source that is faster than cesium.
One of these optical clocks utilizes strontium or rubidium atoms whose frequency "ticks" more than 100 trillion times per second - more than 10,000 times faster than cesium. These atoms can be cooled to near absolute zero in the laser's lattice, reducing noise and improving timekeeping stability.
Clocks and time synchronization are related to national defense and security, social life, all aspects of scientific research, and even some other quantum precision measurement applications need to rely on atomic clocks, therefore, research in the field of clocks has always been a top priority for all countries. In the information age of modern warfare, precision strikes over mass destruction, and the basic means to achieve precision strikes, is a high-precision, highly accurate time and frequency system, the core of which is the atomic clock.
It is recognized that in modern warfare, atomic clocks are even more important than atomic bombs.
Realizing the importance of accurate timekeeping to the future of its maritime leadership, the British Longitude Act of 1714 offered a prize worth over $2 million to promote the development of accurate and stable marine clocks.
Today, governments are similarly funding the development of deployable optical clocks that can be used to address real-world applications.
These clocks have uses far beyond navigation. in 2023, the world will create, store and access more than 100 zettabytes (Zettabyte, a Zettabyte is 1,000 trillion gigabytes) of data, much of it stored in large, globally distributed databases. Each database transaction must be time-stamped (time-stamping) to ensure that the data does not lose synchronization.
For example, if two copies of a financial transaction are stored in separate databases on different continents with a large number of transactions per day, it would be impossible to reconcile a true source without accurate time stamping. Modern data centers house atomic clocks to provide a local source of time; it is inter-integrated with GPS timekeeping to ensure accurate time synchronization.
The resolution of database time stamps is largely a function of clock frequency: the faster the clock, the more transactions can occur in a given time interval; as the world's data needs accelerate, higher application volumes and more efficient data center scaling can be achieved.
The global demand for quantum clocks is primarily driven by the military sector, with aerospace being the primary downstream application. In recent years, the maritime sector has expanded with the development of mobile communications, and the civilian sector has seen a rapid increase in market share and market size.
Market forecast for quantum clocks Source: ICV TAnk
Market share and industry analysis of quantum clocks Source: ICV TAnk
However, according to ICV's forecast, the future of the quantum clock market will grow rapidly in the private sector: the civilian scenario is mainly divided into 46% of basic research, 44% of time frequency, and 10% of other areas.
Regarding future trends, further research on optical and molecular clocks will increase the market for basic research. However, civil 5G and the infrastructure of the information society will allow the market for time and frequency in the civil sector to grow even faster. In the future, quantum clocks are likely to spawn more applications, such as determining altitude by the hourly difference between different altitudes.
Major market players in quantum clocks Source: ICV TAnk
Currently, the commercialized products are mainly various types of microwave atomic clocks (rubidium, hydrogen, cesium clocks), microwave chip-level atomic clocks, and time-frequency synchronization products (protocols). Those being commercialized are optical clocks and chip-scale molecular clocks, for example, the optical cesium atomic clock solution from Oscilloquartz of Switzerland has been deployed at TOYO Corporation in Japan in April 2022.
Overall, the future of quantum clocks will see a relative increase in civilian scenarios compared to the relatively stable military applications, and there may be new applications in the military market - the quantum clock market has huge potential.
Now, more than 300 years have passed since the Longitude Act catalyzed the development of clocks and revolutionized the global economy. It is undeniable that we are standing on the cusp of the commercialization of light clocks, time is the cornerstone of the development of all walks of life, is the most important basic guarantee of measuring the modern scientific process; the highly accurate expression of time allows us to explore the solution of macroscopic mysteries from the microscopic law of atomic oscillation leap.
[1]A Quantum Leap In Timing (forbes.com)
[2]ICV:Quantum Clock Market Research Report-International Cutting-edge-tech Vision (icvtank.com)
[3]2023 Global Quantum Precision Measurement Industry Development Outlook (qq.com)
[4] https://mp.weixin.qq.com/s/yHX070edn5ottB-itSsh6w
