英特爾在量子計算領域的努力開始出成果了。英特爾首次公布旗下的Horse Ridge低溫控制芯片是在兩年前。研究人員日前演示了該技術已經實現了最初的承諾，進而為量子計算機邁向更加實用的階段鋪平了道路。
英特爾與QuTech合作開發出量子控制方法。（圖片：Tim Herman /英特爾公司）
Intel's quantum computing efforts are starting to show tangible results: two years after the company first unveiled its Horse Ridge cryogenic control chip, researchers have demonstrated that the technology is delivering on its original promise, and paving the way for quantum computers to become more practical.
英特爾在量子計算領域的努力開始出成果了。英特爾首次公布旗下的Horse Ridge低溫控制芯片是在兩年前。研究人員日前演示了該技術已經實現了最初的承諾，進而為量子計算機邁向更加實用的階段鋪平了道路。
Practicality, in effect, is not quantum devices' most remarkable trait. In their current format, quantum computers rely on quantum chips that need to be cooled down to extreme temperatures, in order to exert better control over the fragile qubits on the processor. Typically, qubits operate at 20 millikelvin, or about –273 degrees Celsius – temperatures that are even colder than outer space.
實用性目前還不是量子設備可以用來炫耀的特征。目前的量子計算機仍需要被冷卻到極端溫度的量子芯片，目的是可以對處理器上脆弱的量子比特進行更好的控制。通常情況下量子比特在20毫開爾文（大約-273攝氏度）的溫度下運作，這樣的溫度甚至比外太空還要冷。
But to interact with the qubits, whether to control their behavior or read their state, flesh-and-bone scientists work in room-temperature environments, with room-temperature instruments. And since control electronics struggle to perform well at cryogenic temperatures, each qubit has to be linked to the instruments with a single wire.
而科學家們在與量子比特互動（例如控制量子比特的行為或是讀取量子比特的狀態）時都是在室溫環境下進行，儀器也是裝在室溫環境里。由于控制電子裝置在低溫下的性能不佳，每個量子比特都必須用一根電線連在儀器上。
It's easy to see why the set-up might become problematic as scientists contemplate the possibility of scaling up quantum computers to millions of qubits. This hurdle has become known as the "wiring bottleneck".
不難看出，科學家們在考慮將量子計算機的規模擴大到數百萬量子比特時，這樣的設置可能存在一些問題。這個障礙人稱 “布線瓶頸”。
This is why, a few years ago, Intel teamed up with QuTech – a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research – to work on another approach to the problem.
幾年前英特爾與QuTech（Delft理工大學和荷蘭應用科學研究組織之間的合作項目）開始合作研發另一種解決該問題的方法。
It took the form of a new control chip designed to withstand the cold and operate as close as possible to the quantum processor, which Intel unveiled for the first time in 2019. The device was named Horse Ridge – a reference to the coldest place in Oregon, which is also the state where the Intel lab resides.
兩家的研究采用一種新的控制芯片形式，控制芯片需要抵御寒冷并在盡可能接近量子處理器的地方運行，英特爾2019年首次公布了該款芯片。芯片的代號是Horse Ridge——Horse Ridge是英特爾實驗室所處的俄勒岡州最冷的地方。
Horse Ridge was built on Intel's 22-nanometer FinFET Low Power technology, and was presented as a potential way to bring key control functions for quantum computer operations directly into the cryogenic refrigerator, closer to the qubits themselves.
Horse Ridge基于英特爾的22納米FinFET低功耗技術，Horse Ridge旨在能讓量子計算機操作的關鍵控制功能可以置于低溫冰箱里，可以更接近量子比特。
The underlying premise was that, if Horse Ridge could achieve the same level of control as room-temperature instruments, then the wiring bottleneck could be significantly reduced.
但基本前提是Horse Ridge能夠達到與室溫儀器相同的控制水平，那么布線的瓶頸就可以大大減少。
Horse Ridge was subsequently tweaked, and a second generation of the chip was showcased last year; but now, for the first time, Intel's researchers have demonstrated that the technology is as capable of controlling qubits as its room-temperature-based equivalents.
Horse Ridge后來又進行了一些改進，去年展示了第二代Horse Ridge芯片。到了現在，英特爾的研究人員首次證明了Horse Ridge技術能夠像旗下基于室溫的同類產品一樣控制量子比特。
The research team used Horse Ridge to run a two-qubit algorithm called the Deutsch-Jozsa algorithm, and found that the cryogenic chip performed well despite the cold environment, and achieved control of the qubits with a same level of fidelity (99.7%) as room-temperature electronics.
研究小組利用Horse Ridge運行名為Deutsch-Jozsa算法的雙量子比特算法，研究小組還發現盡管環境寒冷，但低溫芯片表現頗佳，而且還實現了量子比特控制，保真度（達99.7%）與室溫電子產品相同。
"Our research results, driven in partnership with QuTech, quantitatively prove that our cryogenic controller, Horse Ridge, can achieve the same high-fidelity results as room-temperature electronics while controlling multiple silicon qubits," said Stefano Pellerano, principal engineer at Intel Labs.
英特爾實驗室首席工程師Stefano Pellerano表示，“我們與QuTech公司合作推動的研究結果從量的角度證明了我們的低溫控制器Horse Ridge在控制多晶片量子比特時可以達到與室溫電子器件相同的高保真結果。”
Horse Ridge is a silicon-based CMOS chip, and as such was designed with a technology similar to that used in conventional microprocessors. The device was adapted to ensure the right operation even at cryogenic temperatures, which enables the chip to manipulate the state of qubits thanks to radio frequency pulses.
Horse Ridge是一款基于硅的CMOS芯片，因此在設計時采用了類似于傳統微處理器的技術。Horse Ridge器件進行過一些修改以確保即使在低溫下也能正確運行，芯片最后可以通過射頻脈沖操縱量子比特的狀態。
The qubits manipulated by Horse Ridge are also silicon-based, contrary to the type of qubits that can be found, for example, in IBM or Google's quantum computers, which are superconducting qubits. While Intel initially pursued both approaches – superconducting as well as silicon qubits – the company's recent efforts have ramped up in the latter.
Horse Ridge操縱的量子比特也是基于硅，與諸如在IBM或谷歌的量子計算機里可以找到的量子比特類型相反，后者是超導量子比特。英特爾最初同時在超導及硅量子比特兩種方法上雙管齊下，但最近加強了在硅量子比特方面的研究工作。
This is because researchers are increasingly acknowledging that building quantum computers with techniques that are similar in nature to those used to produce most modern-day electronics could come with huge advantages when it comes to scaling the technology.
原因是研究人員認識到，如果能用與生產大多數現代電子產品相似的技術來構建量子計算機，在技術規模擴展方面會有巨大優勢。
What's more: with both qubits and the controller chip fabricated in silicon, Intel's researchers are hoping that it may be possible to one day fully integrate them both together in one die or package. This would greatly simplify the wiring challenge of quantum and enable strides in quantum scalability.
更重要的是，由于量子比特和控制芯片都是用硅制造的，英特爾的研究人員希望有一天能夠將二者完全整合在一個芯片或組件里。如此可大大簡化量子的布線并在量子可擴展性方面實現大幅提升。
"These innovations pave the way for fully integrating quantum control chips with the quantum processor in the future, lifting a major roadblock in quantum scaling," said Pellerano.
Pellerano 表示，“這些創新為未來能夠將量子控制芯片與量子處理器完整整合鋪平道路及掃除量子擴展方面的一個主要障礙。”
With these new results, Intel is cementing the company's position in the fast-evolving quantum ecosystem. While much of the focus remains on the qubits themselves, and on improving quantum processors, the Santa Clara giant has established that it is adopting a different course of action, instead working on developing the interconnects and control electronics that will create a quantum stack.
英特爾正在利用這些新成果鞏固自己在快速發展的量子生態系統里的地位。目前的大部分注意力仍然集中在量子比特本身以及改進量子處理器上，但另一方面也顯示這家總部設在圣克拉拉科技巨頭在采取不同的行動方案，而不是致力于開發創建量子堆棧的互連和控制。
Integrating those systems, according to Intel, will be as important a piece of the puzzle to achieve quantum practicality.
據英特爾稱，將這些系統整合在一起必將是實現量子實用性的重要一環。
第9期 2021/05/31
