Physicists are constantly striving to improve the accuracy of atomic clocks, the most precise timekeeping devices in existence. One promising avenue for achieving even greater precision lies in harnessing spin-squeezed states in clock atoms.
Spin-squeezed states are entangled quantum states in which particles work together to cancel out their inherent quantum noise. These states offer incredible potential for quantum-enhanced measurements and metrology. However, creating spin-squeezed states in optical transitions with minimal external noise has been a challenging task.
A team of researchers, led by Ana Maria Rey, has been focusing on utilizing optical cavities to generate spin-squeezed states. These cavities consist of mirrors that allow light to bounce back and forth multiple times. Within the cavity, atoms can synchronize their photon emissions, resulting in a burst of light that is much brighter than what a single atom can produce alone. This phenomenon is known as superradiance. Depending on how superradiance is controlled, it can either lead to entanglement or disrupt the desired quantum state.
In their previous work, Rey and her team discovered that multilevel atoms, with more than two internal energy states, present unique opportunities for harnessing superradiant emission. By inducing the atoms to cancel each other’s emissions, they can create dark states that are immune to superradiance.
Now, in two recently published studies, the team has unveiled a method to not only create dark states in optical cavities but also make these states spin-squeezed. This breakthrough opens up exciting possibilities for generating entangled clocks and pushing the boundaries of quantum metrology.
The researchers found two approaches to preparing highly entangled spin-squeezed states in the atoms. One method involves energizing the atoms with a laser and placing them at special points on the superradiant potential known as saddle points. At these points, the atoms reshape their noise distribution and become highly squeezed. The other method involves transferring the superradiant states into dark states, utilizing specific points where the atoms are close to bright points with zero curvature.
What’s fascinating about these findings is that the spin squeezing can be preserved even in the absence of external laser driving. This transfer of squeezed states into dark states not only maintains the reduced noise characteristics but also ensures their survival.
These discoveries offer new avenues for quantum metrology, allowing for more precise measurements and enhancing the capabilities of atomic clocks. By harnessing dark and entangled states within optical cavities, researchers can unlock the potential of quantum-enhanced technologies and delve deeper into the fascinating world of quantum physics.
FAQ:
1. What are spin-squeezed states?
Spin-squeezed states are entangled quantum states in which particles work together to cancel out their inherent quantum noise. They offer incredible potential for quantum-enhanced measurements and metrology.
2. How can spin-squeezed states be created?
Spin-squeezed states can be created by utilizing optical cavities. These cavities consist of mirrors that allow light to bounce back and forth multiple times. Within the cavity, atoms can synchronize their photon emissions, resulting in spin-squeezed states.
3. What is superradiance?
Superradiance is a phenomenon that occurs when atoms within an optical cavity synchronize their photon emissions, resulting in a burst of light that is brighter than what a single atom can produce alone. Depending on how superradiance is controlled, it can either lead to entanglement or disrupt the desired quantum state.
4. How can dark states be created in optical cavities?
Dark states can be created in optical cavities by manipulating multilevel atoms, with more than two internal energy states. By inducing the atoms to cancel each other’s emissions, dark states that are immune to superradiance can be created.
5. How can the spin squeezing be preserved even without external laser driving?
The spin squeezing can be preserved even in the absence of external laser driving by transferring the squeezed states into dark states within the optical cavities. This transfer not only maintains the reduced noise characteristics but also ensures their survival.
Definitions:
– Atomic clocks: The most precise timekeeping devices that measure time based on the vibrations of atoms.
– Quantum-enhanced measurements: Measurements that utilize quantum systems and principles to achieve higher precision and accuracy.
– Metrology: The scientific study of measurement, including the development of standards and methods for precise and accurate measurements.
– Entanglement: A phenomenon in quantum physics where particles become correlated in a way that the state of one particle cannot be described independently of the state of the other particles.
Related links:
– Atomic Clocks
– National Institute of Standards and Technology – Atomic Clocks
– LIGO – Earth’s Rotation and Atomic Clocks
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