QUANTUM CLOCK

Military infrastructure in Thailand is entirely built relying on a single navigation system, the GPS. All essential services including emergency aids, electricity consumption, vehicle piloting, air traffic control etc., will be put on a total cease at a conflict that leads to the GPS shutdown. Self-development of quantum clocks would result in self-reliance accurate time standard that will equip the military with independent communication and positioning system as well as counterbalance the sole international proprietorship business.

Consumer Electronics

Rubidium Frequency Standard

The hyperfine ground-state transition of 6.834682610904324 GHz from rubidium atoms is used to set forth the 10MHz frequency standard. A miniature module weight less than a cigarette lighter cost less than 1,500 Baht including shipping!

Quantum Tech: A stream of photons emitted from a rubidium discharge lamp get filtered out by using Rb-85 isotopic filter. The light passing through is used to optically pump thermal rubidium-85 atoms in a glass cell to the upper hyperfine ground state, the signal at the light detector behind the glass cell is low. By tuning the MW frequency to the resonance frequency of the hyperfine ground-state transition (6.834682610904324 GHz), the light intensity at the detector regains to its maximum. Finally, the MW signal is divided down to 10MHz for the use as a frequency standard.

Direct Societal Impact: Drone swarm, mobile device positioning, grit battery management, artillery positioning.

Collateral Advantages: Precision agriculture and other mobile consumer electronics.

Alternative Quantum Technology: –

Aided System: –

Defense and Security Applications

Quantum-logic / Atomic / Optical Lattice Clocks

In the past five years, the uncertainty of atomic ticking had increased from 9.46×10^-14 s^-1 (cesium clock) to 2.11 × 10⁻¹⁹ s^-1 (3D quantum gas strontium optical lattice clock) equivalent to 0.1s error over the lifetime of the universe (15 billion years). Such incredible accuracies allow submillimeter resolution for GPS navigation and make detecting small moving objects such as drones possible!

Quantum Tech: Quantum clock technology may be classified into 1) Atomic clock: Ions / Neutral atoms 2) Ion clock: Ions 3) Fountain clock: Neutral atoms (shielding from black body radiation needed) 4) Quantum logic clock: Ions of two species, e.g., Al⁺-Mg⁺ (mimic logical decision making from quantum computing) 5) Lattice clock: 1D Ions / Neutral atoms 1D-3D and 6) Optical atomic clock: Ions / Neutral atoms.

Here at the RCQT, CMU, laser-cooled neutral alkali single atoms are trapped in an optical lattice at the magic wavelength. By tuning an ultra-stable laser frequency to resonance with a preselected narrow-linewidth optical transition of the atoms, the clock frequency is precisely measured, divided, and transferred to MW regime using femtosecond frequency combs.

Direct Societal Impact: GPS navigation.

Collateral Advantages: All systems that require high-precision time synchronization.

Alternative Quantum Technology: –Aided System: Self-referenced mode-locked lasers (femtosecond frequency combs), MASER.