The field of Quantum Computing has been a hot topic in recent years, but many people are still in the dark. Today, let's talk about the core logic of this direction—especially a concept that investors must understand: the fault-tolerant logical Quantum Bit.

**Current Status: Quantum Computing is still in the "excuse phase"

Simply put, current Quantum Computing is in the NISQ stage (Noisy Intermediate-Scale Quantum), which means it can manipulate dozens to hundreds of physical Quantum Bits, but it does not yet have true fault tolerance. What are the major companies doing? They are using dozens to hundreds of physical Bits to encode a small number of error-correcting logical Bits, and then getting them to run stably for a limited time. It's like assembling a barely usable system from a bunch of unreliable parts—inefficient and with limited reliability.

**Where is the breakthrough?

If at some point we successfully develop a fully fault-tolerant logical bit that can run algorithms of arbitrary depth, what does that concept entail?

This is the zero-point breakthrough of Quantum Computing. To make a simple analogy: from a robot that could only run 100 meters, suddenly becoming a machine life that can run a marathon — a qualitative leap.

**What does a fully fault-tolerant logical bit mean?

First, it truly realizes the fundamental unit of Quantum Fault Tolerance (FTQC). In other words:
- Can withstand noise, decoherence, and the continuous accumulation of operational errors
- In theory, the lifespan of quantum information can be extended indefinitely.

Secondly, it can execute quantum circuits of arbitrary depth. This sounds simple, but the value is immense - current quantum computing can only perform quantum gate operations with dozens or hundreds of layers, and there are limitations on depth. Once this limitation is broken, the complexity of the algorithms that can be executed will grow exponentially.

**Why is it so important?

From an investment perspective, this is a key transition point from "demonstrable" to "fault-tolerant". Once achieved, it means that Quantum Computing has moved from laboratory demonstration to a truly usable computational tool.

But the reality is that it will take several years or even more than a decade of engineering breakthroughs to achieve scalable universal Quantum Computing. The road ahead is still long, but the direction is already clear.