Quantum Computers Aren’t What You Think — They’re Cooler | Hartmut Neven | TED

譯者: Wenjer Leuschel 審譯者: Shelley Tsang 曾雯海

I'm Hartmut, I lead Google Quantum AI.

我是哈特穆特 我領導谷歌量子人工智能

I have been working on quantum computing since 2012.

自 2012 年以來 我 一直在從事量子計算

And let me tell you why this is so intriguing.

讓我告訴你 為什麼這如此有趣

Today's computers, like your laptop or a server at a Google data center,

當今的電腦 例如您的筆記本電腦 或 Google 數據中心的服務器

operate on the binary logic of zeros and ones.

根據零和一的二進制邏輯運行

A quantum computer like this one replaces the binary logic

像這樣的量子電腦 用量子物理定律

with the laws of quantum physics that gives it more powerful operations,

取代二進制邏輯 從而使其操作更為強大

allowing it to perform certain computations with way fewer steps.

使其能夠以更少的步驟 執行某些計算

So where does this superpower come from?

那麼這個超能力是從哪裡來的？

Quantum computing is the first technology

量子計算是第一項認真

that takes the idea serious that we live in a multiverse.

認真認為我們生活在 多元宇宙中的想法的技術

It can be seen as farming out computations to parallel universes.

它可以被視為 將計算發展到並行宇宙中

Let me explain.

讓我解釋一下

In quantum physics,

在量子物理中

the key mathematical object

描述許多世界

to describe many worlds is called superposition.

的關鍵數學 對象稱為疊加

To understand what it is, let's look at this simple system.

要了解它是什麼 讓我們看看這個簡單的系統

You just need three bits to describe it.

您只需要三個位元即可描述它

Each coin is a two-state system.

每個硬幣都是一個雙狀態系統

Heads or tails,

頭或尾

zero or one.

零或一

We look at a start state.

我們看一個起始狀態

If I were to know which forces act on the system,

如果我知道哪些力 作用在系統上

then I can predict its trajectory and future states.

那麼我可以預測它的軌跡 和未來狀態

This is how we reason in classical physics and also in everyday life.

這就是我們在古典物理 和日常生活中的理論方式

But if you were to treat this as a quantum system,

但是如果您將它 視為一個量子系統

then it can branch into many configurations simultaneously.

那麼它可以同時分支為 許多配置

And we have to keep track of all those trajectories,

我們必須跟踪 所有這些軌跡

interfere them to make an accurate prediction

干擾它們 以準確預測

of what states we are going to see in the future.

我們將來將 看到什麼狀態

So the equations of quantum mechanics

因此 量子力學方程

tell us that at any time, any object,

告訴我們 在任何時候 任何物體

myself or the world at large,

不論我自己或整個世界

exists in a superposition of many configurations.

都存在於許多配置 的疊加中

Intriguingly, look around in this room.

有趣的是 在這個房間裡四周看看

We are forming a configuration too.

我們也正在構建一個配置

And the equations of quantum physics would suggest

量子物理的方程式 會表明我們

that we sit in different arrangements in different worlds.

在不同的世界中 坐在不同的排列中

This superpower can be applied to computation.

這種超能力 可以應用於計算

Picture a search task.

想像一個搜索任務

By envisioning a very tall closet with a million drawers,

通過想像一個有百萬 抽屜的非常高的衣櫃

I place an item in one of the drawers.

我將一件物品放在抽屜中

How many drawers do you have to open to find the item?

您需要打開多少抽屜 才能找到該物品？

In average it will be half a million,

平均來說 它將是半百萬

but if you had access to a quantum algorithm,

但如果您有權 訪問量子算法

it would only be 1,000 steps to find the item.

則只需 1,000 個步驟即可 找到該項目

How in the world can this be?

到底怎麼會這樣呢？

Indeed, it cannot be in a single world.

事實上 它不能在單一世界中

So here you see a good example

所以在這裡你看到一個很好的例子

of how quantum computing can attain an advantage

關於量子計算 如何通過在平行

by performing computations in parallel worlds.

世界中執行計算 來獲得優勢

Let me show you how to use a quantum computer in practice.

讓我向您展示如何在 實踐中使用量子電腦

So here you see a program in Cirq,

因此您在這裡看到一個用 Cirq

or Python-based programming language to express quantum algorithms.

或基於 Python 的編程 語言的程式來表達量子算法

It looks like sheet music.

它看起來像樂譜

Each line represents a qubit,

每一行代表一個 qubit

and each box represents an operation.

每個方塊代表一個操作

When I hit return,

當我按下回車鍵時

then it gets transmitted to our data center

它就會傳送到我們位於

in Santa Barbara.

聖塔芭芭拉的資料中心。

Here you actually see a live feed of one of our machines.

在這裡您實際上可以看到 我們每台機器的即時直播

Actually, our most powerful quantum computers now have over 100 qubits.

事實上我們最強大的量子電腦 現在擁有超過 100 個量子位元

There, the operations get translated into waveforms,

在那裡這些操作 被轉換為波形

electrical pulses that control the qubits.

這些電脈衝可以控制量子位元

You see how the waveforms change as I change the circuit.

您可以看到當我更改電路時波形 如何變化。

So this is a simple two-qubit circuit performing quantum search.

所以這是一個執行量子搜索的 簡單的雙量子位元電路

For the programmers among you,

對於你們中的程式員

please note how I find one item in a database of four

請注意 我如何只藉由 對數據庫進行一次調用

by only doing a single call to the database.

來找到四個數據庫中的 一個項目

This is something you could not do on an ordinary computer.

這是您無法在 普通電腦上做的事情

So what can you do with quantum computers today?

那麼今天你可以用 量子電腦做什麼？

We have prepared interesting quantum states

我們準備了有 趣的量子狀態

and studied their properties.

並研究它們的屬性

This has led to dozens of publications

這導致在大自然或科學等

in high-impact journals like Nature or Science.

高影響力的期刊上 出了數十種出版物

Actually, I like to think of it as creating little pieces of magic.

實際上我喜歡把它 視為創造小魔法

For example, one state we prepared

例如我們準備的一種狀態

can be thought of as spawning a tiny traversable wormhole.

可以被認為是產生 一個可穿越的小蟲洞

We can use it to learn about the physics of wormholes.

我們可以用它來 了解蟲洞的物理學

We can throw a qubit in

我們可以投入一個 qubit

and see how it reappears on the other side.

看看它如何在 另一側重新出現

We made time crystals.

我們製作了時間水晶

That's a cool word, isn't it?

這是個很酷的單詞不是嗎？

Like, who doesn't want to have a time crystal as an earring?

比如 誰不想把時間 水晶當作耳環呢？

Time crystals have amazing physical properties.

時間晶體具有 驚人的物理特性

They change periodically in time without ever exchanging energy

它們會在時間內 定期變化而不會

with the environment.

與環境交換能量

That's the closest to a perpetual mobile

這是物理定律允許您

that the laws of physics allow you to get.

獲得的最接近永動設備

Or a final example, non-abelian anyons.

或者最後一個例子 非阿貝爾安永

This is a mouthful,

這是一口氣説出来的

but these are systems that change the overall properties

是在交換兩個 相同的部分時改變整

when exchanging two identical parts,

體屬性的系統

something humans have never seen before.

這是人類以前 從未見過的事情

Because envision a little house made of Lego bricks

因為想像一個由 樂高磚組成的小房子

and envision swapping two bricks that look identical.

並想像交換兩個 看起來相同的磚塊

In everyday life, you would not notice a difference,

在日常生活中 你不會注意到差異

but quantum physicists had predicted that systems can exist,

但量子物理學家曾 預測系統可以存在

that exchange or change their properties

當您交換兩個相同的部分時

when you exchange two identical parts.

交換或改變它們的屬性

To date, nobody has performed

到目前為止沒有人

a practical application that can only be done on a quantum computer.

執行了只能在量子電腦上 完成的實用應用程式

Despite what you may have read in the press.

儘管你可能在媒體上 閱讀過的內容

But today, I'm excited to tell you that we are completing the design

但今天我很高興地告訴您 我們正在完成一種可能導致

of an algorithm that may lead to first commercial applications.

第一個商業應用 程式的算法的設計

This quantum algorithm performs signal processing

該量子算法 執行信號處理

to enable new ways to detect and analyze molecules

以使用核電子 旋轉光譜檢測

using nuclear electronic spin spectroscopy.

和分析分子 的新方法

In time, this may lead to exciting consumer applications.

隨著時間的推移 這可能會 導致令人興奮的消費者應用

Envision a device akin to an electronic nose

想像一種類似於 手機或智能手錶中的

in your phone or smart watch.

電子鼻子的設備

Wouldn't it be awesome if your phone could warn you

如果您的手機 能夠警告您將

that you step into a room with dangerous viruses?

進入帶有危險病毒的 房間 那不是很棒嗎？

Or if your smart watch could detect free radicals in your bloodstream

或者如果您的智能手錶 可以檢測血液中的自由基

and tell you it's time to drink your acai juice,

並告訴您是時候 喝 Acai 汁了

or warn you of allergens in food

或者警告您食物中的過敏原

or many other truly helpful use cases.

或許多其他真正有用的使用案例

To unlock more applications,

要解鎖更多應用程式

you will need to build a large error-corrected quantum computer.

您將需要構建一個大型錯誤 更正的量子電腦

Here you see our road map.

在這裡你看到我們的路線圖

How to build a computer with a million physical qubits.

如何構建一台具有百萬 物實體量子位元的電腦

It consists of six milestones.

它包括六個里程碑

and we achieved already the first two.

我們已經實現了前兩個

Prior to 2019,

在 2019 年之前

nobody had shown a beyond classical computation on a quantum computer.

沒有人在量子電腦上 展示了超過經典的計算

We were the first to demonstrate it.

我們是第一個展示它的人

Our chip could perform a computation

我們的芯片可以執行當時

that the then-fastest supercomputer would have needed 10,000 years to do.

最快的超級電腦需要 10,000 年才能完成的計算

But recently, we repeated this experiment.

但最近我們重複了這個實驗

And now, Frontier, today's top supercomputer,

現在當今頂尖的超級電腦 Frontier

would need one billion years to perform this computation.

需要十億年才 能執行這種計算

This dramatic growth in compute power corroborates Neven's Law,

計算功率的這種巨大增長 證實了 Neven 定律

which says that the power of quantum computers will grow

該定律表示量子電腦的 力量將以兩倍指數的

at a double exponential rate.

速度增長

In 2023, we achieved the second milestone.

2023 年我們實現了第二個里程碑

We demonstrated again for the first time

我們再次展示了量子

that quantum error correction is a scalable technology.

錯誤校正是一種 可擴展的技術

Error correction sounds boring, but it's crucial.

錯誤修正聽起來很無聊 但這是很重要的

Today, our two-qubit operations have an error rate of 1 in 1,000.

今天我們的雙量子位元運算的 錯誤率為 1,000 分之一

That means that in every 1,000 steps or so,

這意味著每 1000 個 步驟左右

the quantum computer will crash.

量子電腦將崩潰

To improve this,

為了改善這一點

we combine many physical qubits to a logical qubit

我們將許多實體等位 組合成邏輯量子位元

to reduce the error rate to 1 in a billion or even less.

將錯誤率降低到一億分之一 甚至更少

We are about halfway through our road map,

我們已經完成路線圖的一半

and we are optimistic that we will complete it

我們樂觀 我們將在

before the end of this decade.

這十年結束之前完成它

We have done analytical and numerical studies

我們已經進行 分析和數值研究

to predict which algorithms will be impactful

以預測哪些算法 將對如此大的

on such a large quantum computer.

量子電腦產生的影響

A class of applications we like and we call Feynman's killer app,

我們喜歡的一類應用程式 我們稱為 Feynman 的殺手應用程式

is the simulation of systems where quantum effects are important.

是對量子效果 很重要的系統模擬

This is relevant for designing more effective,

這對於設計更有效 更有

more targeted medicines.

針對性的藥物有關

Specifically, we have worked with a pharmaceutical company

具體來說 我們與一家製藥公司

on algorithms to describe cytochrome P450.

合作研究演算法來描述細胞色素 P450

This group of enzymes metabolizes about 75 percent of the drugs we take.

這組酶代謝大約我們服用的藥物的 75％

Or the design of lighter, faster-charging batteries

或是更輕、更快充電的 電池的設計

that can hold a larger charge for electric cars

可以為電動汽車 甚至電動飛機承載

or even electric airplanes.

更大的電量

Or to hasten the design of fusion reactors to help with climate change,

或是加快融合反應器的設計 以幫助應對氣候變化

arguably humanity's most urgent challenge.

這可以說是人類最緊急的挑戰

A recent result is a novel algorithm

最近的結果是一種新穎的算法

that delivers significant speed up for optimization.

可以大幅提高 優化的速度

This is a big deal

這是一個很大的問題

because optimization problems are ubiquitous

因為優化問題在 工程 金融或

in engineering, finance or machine learning.

機器學習中 無所不在

A way to think about this result is in the future,

考慮這一結果的 一種方法是在未來

when an AI will play chess or Go against the quantum AI,

當人工智能將打國際象棋 或與量子人工智能對抗時

the quantum AI will win.

量子人工智能將贏得勝利

This result shows that quantum computers

這個結果表明量子電腦

will become a must-have capability

將成為服務基礎計算

to serve foundational computational tasks.

任務的必備能力

I'm also very interested in the intersection of physics

我也對物理和神經 生物學的交叉

and neurobiology.

感到興趣

Quantum information science

量子信息科學

may enable us to answer one of humanity's deepest questions:

可能使我們能夠回答 人類最深的問題之一：

What creates conscious experience?

是什麼創造了意識的體驗？

An attractive conjecture is that consciousness

一個有吸引力的 猜測是意識

is how we experience the emergence

是我們在多元宇宙所

of a single classical world

構成的許多宇宙中

out of the many the multiverse is composed of.

體驗單一經典世界的 出現的方式

With academic collaborators,

與學術合作者一起

I have started a program to experimentally test this conjecture

我開始了一個計劃 以使用量子神經生物學方法

using methods of quantum neurobiology.

實驗測試這個猜測

If our conjecture is correct,

如果我們的猜測是正確的

this would allow us to expand human consciousness in space,

這將使我們能夠 在空間 時間和複雜性中

time and complexity.

擴大人類的意識

In conclusion,

總之

we are making steady progress

我們正在努力打造世界上

towards building the world's first useful quantum computer

第一台有用的量子電腦 並將其巨大的力量

and applying its enormous power to important challenges.

應用於重要挑戰方面 取得穩定的進展

A quantum computer will be a gift to future generations,

量子電腦將是 給未來一代的禮物

giving them a new tool to solve problems that today are unsolvable.

為他們提供一種新的工具來解決 當今無法解決的問題

Thank you.

謝謝

(Applause)

（掌聲）