When it comes to pushing materials to their absolute limits, nothing beats the sheer, unrelenting force of petapascal (PPa) and terapascal (TPa) pressures. At these extremes—where pressures exceed 1 million times Earth's atmospheric pressure—materials don't just bend or break; they transform into entirely new states of matter. Welcome to the wild world of high-pressure physics, where diamond anvils become the ultimate pressure cookers and quantum behaviors emerge from chaos.
The diamond anvil cell (DAC) is the unsung hero of extreme pressure research. These devices use two lab-grown diamond tips to compress samples to pressures that would make even a neutron star raise an eyebrow (if it had one). Here's why diamonds are the perfect tool:
Recent advances in CVD (chemical vapor deposition) diamond growth have enabled anvils that can sustain over 1 terapascal (1,000 gigapascals) without failing catastrophically. That's equivalent to stacking 100 Eiffel Towers on your pinky finger—if your pinky finger were made of unicorn tears and unobtanium.
Under terapascal pressures, materials exhibit behaviors that defy textbook chemistry. Electrons get shoved into higher energy states, atomic orbitals distort into bizarre shapes, and conventional chemical bonds become irrelevant. Some observed phenomena include:
Materials like hydrogen (normally an insulating gas) become metallic at ~500 GPa. At terapascal pressures, even noble gases like xenon are forced into conducting states. This has massive implications for planetary science—Jupiter's core may contain metallic hydrogen oceans!
Certain hydrides (LaH10, YH9) show superconductivity at near-room temperatures when compressed to 150-200 GPa. The terapascal regime may host even more exotic superconducting phases.
At these pressures, electrons:
Only a handful of facilities worldwide can reach terapascal pressures. The current record holders include:
| Institution | Maximum Pressure Achieved | Notable Discoveries |
|---|---|---|
| University of Bayreuth | 1.1 TPa (2023) | New carbon allotropes |
| Carnegie Institution for Science | 0.9 TPa (2022) | Metallic nitrogen phases |
| Shanghai Jiao Tong University | 0.85 TPa (2021) | Superionic water ice |
Reaching these pressures isn't for the faint-hearted. Researchers face:
Even diamonds have limits. At ~1.3 TPa, the carbon-carbon bonds begin to shear. Solutions being explored:
Standard pressure markers (ruby fluorescence, gold standards) become unreliable above 300 GPa. New methods using:
Density functional theory (DFT) simulations predict several terapascal wonders:
Certain ternary hydrides may superconduct above 250 K at ~1 TPa based on computational studies. Experimental verification pending.
Theoretical work suggests possible:
The next frontier involves:
Laser-driven shockwaves can briefly achieve multi-terapascal pressures (5-10 TPa) for nanoseconds—enough to probe new states.
Neural networks are being trained to predict stable high-pressure phases before synthesis attempts.
NV centers in diamond may enable magnetic field measurements at terapascal pressures.
The terapascal regime represents one of the last great experimental frontiers in condensed matter physics. Each increment in pressure capability reveals phenomena that challenge our understanding of quantum mechanics and materials science. As diamond anvil technology improves, we may soon probe pressures rivaling those inside white dwarf stars—all from a benchtop setup that makes even the Large Hadron Collider look low-tech by comparison.