Hundreds of companies and universities have joined together to try to create quantum computers that are both powerful and useful. Researchers in Israel have achieved results that make quantum computing viable. 

Quantum computers moving forward, where is Israel?

The first quantum computer was built in 1982, and since then researchers have been working diligently to build even larger quantum computers. In 2017, IBM introduced their 14-qubit machine, which they claim is the first ever working quantum computer. Since then hundreds of companies and universities have joined together to try to create quantum computers that are both powerful and useful. There is currently no way to use these machines to find a cure for cancer, but it could help us understand how cells work at the atomic level.

Although we do not yet know what practical uses quantum computers could provide, we already know they exist in nature. An example of this is in photosynthesis, the process in which plants convert sunlight and water into sugar. Photosynthesis occurs in two parts: the light reaction (which converts light energy into chemical energy) and the dark reaction (which converts carbon dioxide into glucose). The dark reaction utilizes quantum effects, and scientists believe that in order to fully understand how this works, we need to build a quantum computer. By using a quantum computer, we may be able to gain insight into how plants convert solar energy into chemical energy.

Quantum computers are still far away from being mainstream, but they are progressing at a rapid rate. Researchers at the Weizmann Institute in Israel are leading the research in developing these devices, and they hope to have a functioning device in 2020. They are planning to develop a 20-qubit computer, which would mean we would have access to enough computing power to make these machines commercially viable.

Israel is considered a hotbed for technology due to a vibrant culture surrounding science. Many Israeli universities, including Technion and Tel Aviv University, have created programs specifically geared towards advancing technological advances. While many countries are afraid of adopting quantum computers due to the potential threat they pose to national security, Israel is taking a different approach by embracing them.

 

Quantum computing

A quantum computer is a theoretical device constructed from microscopic particles called cubits (quantum bits) that store their data in superposition rather than the 0's and 1's we use today. In contrast to classical computers, whose memory consists of binary states, a quantum bit can exist in both states at once, meaning information can be stored and processed simultaneously. While scientists have long theorized about how to build a working quantum computer, they had previously found it challenging to do so due to the need to control quantum objects over distances greater than 10 nanometers—in other words, at scales much smaller than a single atom. So while many researchers were excited by the prospect of building a functional quantum computer, progress remained elusive. But now, researchers in Israel have achieved results that make quantum computing viable.

The Israeli team first demonstrated that an electron trapped inside a semiconductor quantum dot could be controlled using a microwave field. By doing so, the team successfully created a "cubit," the fundamental unit of computation used by quantum computers. The team then showed that this cubit could be used to store quantum information, and that this information could later be retrieved. In addition to demonstrating that quantum information can be stored and retrieved, the team also showed that the cubit can communicate with other cubits, even across space. Specifically, the team was able to transfer the state of one cubit to a separate location within the same chip. To prevent any potential errors from affecting the transferred state, the team added a protective layer around each cubit.

In order to move beyond proof-of-concept demonstrations and toward practical applications, the team is currently researching ways to minimize the effects of noise and decoherence, two phenomena that cause cubits to lose their information. One way to mitigate these issues is to increase the coherence time of quantum systems. Coherence refers to the length of time that a cubit retains its quantum properties before losing them entirely. Currently, the longest coherent times achieved in laboratories are only tens of microseconds, well below what would be necessary for commercial applications. However, the team says that they hope to improve this metric significantly with further research. Another approach to controlling decoherence is to develop new technologies to manipulate individual electrons. If successful, these techniques could open new frontiers in quantum science.

Where Is Israel?

Israel is located between the Mediterranean Sea and Africa, and borders Egypt to the south, Lebanon to the north, Jordan to the east, Syria to the west, and the Palestinian territories to the northwest. The country covers roughly 30,000 square kilometers, making it the world's smallest nation by area. Its capital city is Jerusalem, which is recognized by the United Nations as being occupied territory. The current government dates back to 1948, after the end of the British Mandate of Palestine, and consists of a center-right coalition led by Prime Minister Benjamin Netanyahu.

How Does Israel Benefit From Quantum Computing?

Since a quantum computer relies upon the unique properties of matter, the existence of a functioning quantum computer poses significant challenges to physics. Among the most difficult problems is determining whether a system is in a pure state or a mixed state. A pure state refers to a system that is completely described by its quantum properties; a mixed state describes a system that may possess some quantum properties yet not others. Because of the inherent uncertainty associated with quantum systems, physicists believe that it is impossible to know for certain if a system is in a mixed state unless the system is observed. Therefore, observing a quantum system changes its state, effectively destroying the original data. As a result, quantum computers require error correction schemes to determine whether a given system is in a pure or mixed state. These schemes essentially allow quantum bits to exchange information via methods similar to those used in modern computers.

The problem facing the Israeli group is that, prior to their work, no one knew how to control and observe individual spins in silicon quantum dots without annihilating them. The solution proposed by the team involved trapping electrons in silicon quantum dots and using microwaves to interact with the spin of the electrons. When the team applied a magnetic field, it caused the electrons to become polarized, and when they removed the field, the electrons returned to their unpolarized state. In their paper published in Nature Communications, the team reported several experiments that demonstrated the basic principles behind their process. The team also demonstrated that the polarization could be used to store and retrieve quantum information.

To enable future applications, the team is developing ways to isolate the cubits from external influences and to protect them from environmental perturbations. In addition, the team will investigate ways to expand the range of materials that can host the cubits. Finally, the team plans to study the feasibility of building larger quantum networks using existing technology.