Name: 拓撲量子物質究竟是什麼？- 張帆 (What in the world is topological quantum matter? - Fan Zhang)
Uploaded: 2024-11-28T17:11:43.000Z
Duration: 5 min 3 s

進階被動語態

What if electricity could travel forever without being diminished?

如果電能可以永遠傳輸而不被削弱會怎樣？

What if a computer could run exponentially faster with perfect accuracy?

如果計算機能以指數級的速度運行，而且精確度極高，那會怎樣？

What technology could those abilities build?

We may be able to find out thanks to the work of the three scientists who won the Nobel Prize in Physics in 2016.

得益於獲得 2016 年諾貝爾物理學獎的三位科學家的工作，我們或許能夠找到答案。

David Thouless, Duncan Haldane, and Michael Kosterlitz won the award for discovering that even microscopic matter at the smallest scale can exhibit macroscopic properties and phases that are topological.

David Thouless、Duncan Haldane 和 Michael Kosterlitz 因發現即使是最小尺度的微觀物質也能表現出宏觀特性和拓撲相而獲獎。

First of all, topology is a branch of mathematics that focuses on fundamental properties of objects.

首先，拓撲學是數學的一個分支，主要研究物體的基本屬性。

Topological properties don't change when an object is gradually stretched or bent.

當物體逐漸拉伸或彎曲時，拓撲特性不會改變。

The object has to be torn or attached in new places.

物品必須被撕裂或粘貼到新的地方。

A donut and a coffee cup look the same to a topologist because they both have one hole.

對於拓撲學家來說，甜甜圈和咖啡杯看起來是一樣的，因為它們都有一個洞。

You could reshape a donut into a coffee cup, and it would still have just one.

你可以把一個甜甜圈改成一個咖啡杯，但它仍然只有一個。

On the other hand, a pretzel has three holes.

另一方面，椒鹽脆餅有三個孔。

There are no smooth incremental changes that will turn a donut into a pretzel.

沒有什麼平穩的漸進式變化能讓甜甜圈變成椒鹽脆餅。

For a long time, it wasn't clear whether topology was useful for describing the behaviors of subatomic particles.

長期以來，人們並不清楚拓撲學對描述亞原子粒子的行為是否有用。

That's because particles, like electrons and photons, are subject to the strange laws of quantum physics, which involve a great deal of uncertainty that we don't see at the scale of coffee cups.

這是因為像電子和光子這樣的粒子受制於奇特的量子物理定律，而量子物理定律涉及大量的不確定性，我們在咖啡杯的尺度上看不到這些不確定性。

But the Nobel laureates discovered that topological properties do exist at the quantum level.

但諾貝爾獎得主發現，拓撲特性在量子層面確實存在。

And that discovery may revolutionize materials science, electronic engineering, and computer science.

這一發現可能會徹底改變材料科學、電子工程和計算機科學。

That's because these properties lend surprising stability and remarkable characteristics to some exotic phases of matter in the delicate quantum world.

這是因為在微妙的量子世界中，這些特性賦予了一些奇異的物質相以驚人的穩定性和非凡的特性。

One example is called a topological insulator.

If a strong enough magnetic field passes through them, each electron will start traveling in a circle, which is called a closed orbit.

如果有足夠強的磁場穿過它們，每個電子就會開始繞圈運行，這就是所謂的閉合軌道。

Because the electrons are stuck in these loops, they're not conducting electricity.

由於電子被卡在這些環路中，它們無法導電。

But at the edge of the material, the orbits become open, connected, and they all point in the same direction.

但在材料的邊緣，軌道變得開放、相連，並且都指向同一個方向。

So electrons can jump from one orbit to the next and travel all the way around the edge.

是以，電子可以從一個軌道躍遷到下一個軌道，並一直繞著邊緣運行。

This means that the material conducts electricity around the edge, but not in the middle.

這意味著材料的邊緣導電，但中間不導電。

This conductivity isn't affected by small changes in the material, like impurities or imperfections.

這種導電性不會受到材料微小變化（如雜質或瑕疵）的影響。

That's just like how the hole in the coffee cup isn't changed by stretching it out.

這就像咖啡杯上的洞不會因為拉伸而改變一樣。

The edge of such a topological insulator has perfect electron transport.

這種拓撲絕緣體的邊緣具有完美的電子傳輸。

No electrons travel backward, no energy is lost as heat, and the number of conducting pathways can even be controlled.

沒有電子逆向移動，沒有能量以熱量形式損失，甚至可以控制導電通路的數量。

The electronics of the future could be built to use this perfectly efficient electron highway.

未來的電子設備可以利用這條高效的電子高速公路。

The topological properties of subatomic particles could also transform quantum computing.

亞原子粒子的拓撲特性也能改變量子計算。

Quantum computers take advantage of the fact that subatomic particles can be in different states at the same time to store information in something called qubits.

量子計算機利用亞原子粒子可以同時處於不同狀態這一事實，將資訊存儲在稱為量子比特的東西中。

These qubits can solve problems exponentially faster than classical digital computers.

這些量子比特解決問題的速度比傳統數字計算機快數倍。

The problem is that this data is so delicate that interaction with the environment can destroy it.

問題是，這些數據非常脆弱，與環境的交互會破壞它們。

But in some exotic topological phases, the subatomic particles can become protected.

但在某些奇特的拓撲階段，亞原子粒子會受到保護。

In other words, the qubits formed by them can't be changed by small or local disturbances.

換句話說，由它們形成的量子比特不會因微小或局部干擾而改變。

These topological qubits would be more stable, leading to more accurate computation and a better quantum computer.

這些拓撲量子比特將更加穩定，從而帶來更精確的計算和更好的量子計算機。

Topology was originally studied as a branch of purely abstract mathematics.

拓撲學最初是作為純抽象數學的一個分支進行研究的。

 Thanks to the pioneering work of Thouless, Haldane, and Kosterlitz, we now know it can be used to understand the riddles of nature and to revolutionize the future of technologies.

由於圖裡斯、霍爾丹和科斯特利茨的開創性工作，我們現在知道，它可以用來理解自然之謎，並徹底改變未來的技術。

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拓撲量子物質究竟是什麼？- 張帆 (What in the world is topological quantum matter? - Fan Zhang)

stick

material

stretch

delicate