PhD, École Polytechnique Fédérale de Lausanne
Advancements and challenges in quantum computers and quantum networks
Over the past few decades, from a long standing effort by generations of scientist trying to understand the fundamentals of quantum mechanics, new concepts has emerged which is known as quantum computers and quantum networks. These platforms take advantage of parallel interaction between quantum two level systems – known as quantum bits (qbit) – in order to deliver efficient and novel techniques for some of the computational tasks that is either impossible or extremely difficult to solve via classical computers. This opens a new era in computer science not only to extend our computational capabilities but also paves the way for an unexplored regime that previously was not accessible with classical computers. On the other hand, quantum laws can be used in secure communication. Over the past years, scientist introduced several communication protocols that are impossible to hack and its security is guaranteed by the fundamental laws of quantum mechanics. These mostly theoretical achievements has raised interest among many researchers around the world in order to realize the quantum computers and quantum communication. In this talk we will review some of the basics of quantum computers and quantum communication protocol and their advantages compare to classical computers and finally discuss the experimental challenges in creating these platforms. In this talk, we start by reviewing some basics about quantum mechanics, especially how quantum computers and quantum communication protocols are deeply connected to the concepts of entanglement and act of measurements in quantum mechanics. Then we briefly review the building blocks of quantum computers, known as quantum gates and the basic working principles of quantum computers. In the next step we discuss how quantum computers can solve some class of computational tasks in a more efficient way by taking advantages of their large Hilbert space and briefly introduce the Shor’s algorithm as an example. Next we review some of the experimental challenges in building the quantum computers and especially discuss how temperature pose a fundamental limit on quantum computers via the process of thermal decoherence. Next we briefly introduce several experimental platforms such as superconducting circuits, atom trapping and etc. which was studied by researchers in recent years. Finally we will see in more details how nanomechanical oscillator can play a role as a novel platform for some applications in quantum computer domain such as quantum memories and quantum transducers.

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