From: lexfridman
Quantum supremacy is a term used to describe the milestone in quantum computing where a quantum computer performs a computation significantly faster than the best possible algorithm on a classical computer for the same task. This groundbreaking concept signifies a fundamental shift in computational capabilities, illustrating a pivotal moment where quantum machines can outperform classical devices on specific tasks.
> [!info] Origin of the Term
>
> The term "quantum supremacy" was coined by physicist John Preskill in 2012 to describe the moment when quantum computers can unequivocally solve problems beyond the reach of classical computers <a class="yt-timestamp" data-t="00:56:47">[00:56:47]</a>.
## Google's Milestone
In 2019, Google announced that it had achieved quantum supremacy with a 53-qubit quantum computer named Sycamore. Specifically, Google used Sycamore to perform a task that would reportedly take the world's most powerful supercomputers about 10,000 years to complete, an accomplishment Google claimed took their quantum processor merely 200 seconds <a class="yt-timestamp" data-t="01:02:23">[01:02:23]</a>.
### The Experiment
Google's task was a "sampling problem" based on generating samples from a complex probability distribution <a class="yt-timestamp" data-t="01:03:15">[01:03:15]</a>. This type of problem doesn't have a direct application but serves to demonstrate the raw computational power unique to quantum machines.
The supremacy demonstration involves applying a series of random quantum operations to qubits, creating an output distribution of probabilities <a class="yt-timestamp" data-t="01:05:01">[01:05:01]</a>. Google's achievement was validated using statistical tests developed to verify whether these distributions could only be generated by a quantum computer within a feasible time frame <a class="yt-timestamp" data-t="01:06:33">[01:06:33]</a>.
### Challenges and Considerations
1. **Error Correction**: Google's experiment utilized raw, non-error-corrected qubits, which are susceptible to noise and decoherence. The development of error-corrected qubits remains crucial for further progress in practical quantum computing applications <a class="yt-timestamp" data-t="00:44:28">[00:44:28]</a>.
2. **Verification**: Verifying the output of quantum computers is challenging but necessary. Google's experiment struck a balance where classical computers can partially simulate and verify quantum outputs, crucial at this stage for validating results <a class="yt-timestamp" data-t="01:06:02">[01:06:02]</a>.
3. **Usefulness**: While the experiment did not solve a classically intractable but practically useful problem, it set the stage for future advancements that might address significant real-world applications, such as quantum simulation in chemistry and materials science <a class="yt-timestamp" data-t="01:17:13">[01:17:13]</a>.
## Broader Implications
Quantum supremacy is a critical benchmark rather than a practical endpoint. While it signifies a historic moment in computation, it also highlights the beginning of a new era that will focus on achieving error correction, generating useful quantum algorithms, and eventually, practical quantum computing capabilities. Current challenges include scaling to large numbers of qubits, improving qubit quality, and developing robust quantum algorithms <a class="yt-timestamp" data-t="01:22:28">[01:22:28]</a>.
> [!tip] Future Outlook
>
> The potential applications of quantum computing extend to fields like cryptography, optimization, and complex system simulations, promising revolutionary changes in industries ranging from healthcare to finance <a class="yt-timestamp" data-t="01:18:00">[01:18:00]</a>.
The journey from quantum supremacy to practical, widespread quantum computing is a pivotal scientific endeavor, poised to redefine the boundaries of computation and problem-solving in the coming decades.