Friday is here, and the 'A Taste of Science for the Weekend' column is back — number 68.
This time: the fascinating and extraordinary connection between lab-grown diamonds, chips, and quantum computing.
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The lab-grown diamonds we all know can be created in two ways:
One way is to place carbon in a chamber under enormous pressure and temperature, simulating the conditions deep within the Earth where natural diamonds form.
The second way is through a process called CVD, in which a plasma-containing carbon gas crystallizes onto tiny diamond seed crystals over six weeks, producing an exceptionally pure and beautiful diamond crystal.
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Lab-grown diamonds are already widespread in industry — for cutting hard materials or drilling, for example — as well as in the world of jewelry.
Their price continues to fall steadily, posing a growing challenge to the natural diamond market.
But without our realizing it, they may soon become a critical component in the semiconductor industry.
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The processors we manufacture are becoming faster and faster — partly because shrinking transistors increases their count on a chip, and partly because rising clock speeds allow them to perform operations at tremendous rates.
The problem is that a portion of the processors' energy consumption turns into heat.
This heat concentrates at specific nodes within the chip, and there is a critical need to drain it outward as quickly as possible before the chip suffers irreparable damage.
Diamonds can conduct that heat away from the chip at roughly five times the efficiency of copper, making them the most effective heat-conducting material in nature.
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Heat conduction in diamond differs from that in copper.
In copper, electrons moving from atom to atom carry thermal energy along with them.
Diamond, by contrast, is a lattice of atoms strongly bonded to one another, and thermal energy travels through the vibration of atoms in place.
This thermal energy is transferred in discrete packets known in physics as 'phonons.'
Adding a diamond layer on top of chips can significantly boost their clock speeds and processing capabilities while maintaining normal operating temperatures — effectively opening up an entire world of processing power that was previously impossible.
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Another field in which diamonds are critical is quantum computing.
Quantum computers are based on qubits — atoms that are highly sensitive to disturbances such as heat or electromagnetic interference.
For this reason, they must be well isolated at temperatures close to absolute zero, requiring massive and extremely expensive cooling and isolation systems.
To address this problem, pure diamonds are doped (their purity intentionally reduced) by introducing nitrogen atoms and lattice vacancies — sites in the diamond lattice with no atom present.
These tiny defects in the lattice structure function as qubits even at room temperature, because the rigid structure of the diamond shields them from interference while simultaneously allowing the laser beams that operate the qubits to pass through.
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In the chip domain, the main remaining challenge is bonding diamond chips to silicon, since diamond is a hard material that does not bond easily to other substances.
Several companies are already working energetically in this space, and there is no doubt that this fascinating world will continue to surprise us and enable breakthrough technologies in the years ahead.
Shabbat Shalom 😊
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Video credit: From a BBC channel report on YouTube.
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