From: allin
Google has announced significant advancements in quantum computing with its latest quantum chip, named Willow [02:00:04].
Development and Capabilities
The Willow chip was fabricated in Google’s new chip plant in Santa Barbara [02:13:08]. The company initiated its quantum computing project back in 2012 [02:16:17].
Willow performed a standard benchmark computation in under five minutes [02:24:25], a task that would have taken today’s fastest supercomputers 10 septillion years, or 10 to the 25th power [02:26:30]. This duration is billions of times older than the universe [02:32:32].
Quantum Computing Fundamentals
Traditional computers operate using binary bits (ones and zeros) [02:38:40], whereas quantum computers utilize qubits, which can be zero, one, or both simultaneously [02:44:46]. A quantum bit (qubit) can be thought of as a wave function, representing a quantum state of a molecule [02:56:00]. The ability to contain and interact with these quantum states allows for quantum computation [03:04:06].
Key quantum phenomena include:
- Entanglement: Two molecules can relate to one another at a distance [03:38:40].
- Interference: Qubits can cancel out each other’s wave functions [03:42:44].
Quantum computing enables entirely new algorithms that can perform tasks not possible or intuitive on traditional computers [03:04:06].
Logical Qubits and Error Correction
A significant challenge in quantum computing is building a quantum computer with multiple qubits that maintain their state for a sufficient period without accumulating too many errors [02:22:24]. Google demonstrated the creation of “logical qubits” by combining several physical qubits [02:41:00]. This approach uses an algorithm to balance the error rates of individual physical qubits [02:54:56]. For the first time, Google showed that increasing the number of combined qubits (e.g., from 3x3 to 5x5 and then 7x7) led to a decrease in the error rate [03:00:00]. This marks an important milestone, as it confirms a technical architecture for building a chip with multiple interacting qubits at a sufficiently low error rate for quantum calculations [03:27:00].
Implications and Applications
One of the most interesting areas for quantum computing is cryptography [03:32:00]. Shor’s algorithm, developed by a professor at MIT, theorized that a quantum computer could factor numbers almost instantly [03:43:00]. All modern encryption standards, including RSA and SHA-256 (used in Bitcoin’s blockchain), are based on number factorization [03:59:00]. A quantum computer could potentially break these codes in seconds or minutes [04:25:00].
If Google continues on its current trajectory, large-scale quantum computers could potentially crack all current encryption standards in a few years (estimated 2-5 years) [03:58:00]. This necessitates a global transition to post-quantum encryption standards [04:15:00].
Challenges and Future Outlook
Despite the breakthroughs, there are significant challenges ahead:
- Fault Tolerance: Google’s target for a logically useful quantum chip is a fault tolerance of 1 x 10^-6 [03:59:59]. The Willow chip currently operates at 99.7% (or 3 x 10^-3 error rate), indicating a need for several orders of magnitude improvement [04:12:00].
- Verification: It is challenging to verify the accuracy of the quantum computation’s results, as standard computing would take an unfeasibly long time to confirm them [03:38:00].
- Practicality and Software: Even if a quantum computer becomes accurate and fast, new software will need to be written from scratch, as nothing from current computing maps directly to quantum operations [03:53:00]. This presents a potential business opportunity for developing application layers and compilers for quantum systems [03:33:00].
The development of quantum computing is compared to the “Shockley transistor moment” [03:28:00], signaling a foundational step towards future advancements. Google’s ability to fund such long-term, high-risk research is attributed to its highly profitable search business [04:14:00].
Multiverse and Quantum Mechanics
Google’s announcement included a statement that the performance jump “lends credence to the notion that quantum computation occurs in many parallel universes in line with the idea that we live in a Multiverse” [03:29:00]. This statement is rooted in the non-intuitive nature of quantum physics [03:44:00]. A key concept is that a qubit exists in a superposition of multiple states simultaneously until it is observed, at which point it collapses to a single value [04:33:00]. This observation effect on particles is a well-known aspect of quantum mechanics [04:09:00].