What is the Quantum Computing? (Week 2)

Introduction

• In the last years, we witnessed a huge grow of the Computing Power, with constantly improvements in the computation machines, technological devices, desktops, laptops, smartphones, among many others we use in our quotidian.

• Then, began the emergence of the Internet, considered by many experts, the biggest technological achievement of the XXI century, which allow us, to be connected with each other all the time.

• The Internet has suffered a huge evolution in recent years and, its number of users, as well as the amount of data processed continues to grow!!!

• Some experts also call this era of the Era of the Information, or even, more recently, the Internet of Things, making constantly use of some new technologies like Distributed Systems, Cloud Computing, Fog Computing and Edge Computing, among many others!!!

• It's predicted that in the near future, all the daily objects around the world will start to become connected between them, forming huge networks, sharing and consuming, information and data, constantly...

• Many of today’s applications which make use of it need large transfers between devices and data centers.

• According to Cisco, in 2017, was estimated that by 2021, the total number of smartphones and its connections (including handsets) will represent close to 50% of the total global mobile devices and connections (5.5 billion). In 2016, this number was estimated in 4.9 billion.

• With this huge and exponential grow of, technology and information, started to become more critical than ever, the need of powerful devices capable of process all this data in a more effective fashion way and faster than ever, with no faults, among other many aspects, in order to keep the information always available, no matter what!!!

• In the last years, with this new kind of technological trends, it's being rised several concerns and problems about users' data privacy and rights, as legal, moral and ethic aspects, where sometimes, the current Cybersecurity and Classical Cryptography can't offer guarantees of fundamental security properties of users and data, such as, confidentiality, integrity, availability and authentication, or can't give us the necessary secure communications at all, in our quotidian.

• Other aspect to take in consideration is that, even the most powerful Conventional Computers of the current days can't solve all the problems...

• Some interest and research areas like, per example, Sciences, Mathematics, Chemistry, Physics, Artificial Intelligence, Machine Learning, Theory of Complexity, Cryptography, among many others, already showed us that, there are yet some complex problems that can't be solved at a polynomial time or even, solved at all, due to the existing limitations of computation present in the current Conventional Computers...

Moore's Law

• Gordon Moore, the co-founder and chairman emeritus of Intel Corporation, predicted through an observation's paper, in 1965 and reviewed in 1975, that the number of transistors in a dense integrated circuit chips doubles about every two years. This observation was named, at the time, the Moore's Law.

• Initially, in 1995, this paper described a doubling every year in the number of components per integrated circuit, and projected this rate of growth would continue for at least another decade. But in 1975, looking forward to the next decade, it was revised to doubling this phenomenon every two years, a Compound Annual Growth Rate (C.A.G.R.) of 41.4%.

• This was very good news at the beginning and lasted a long time but everything that's good end fast and don't last forever...

• And so, most semiconductor industry forecasters, experts and researchers, including Gordon Moore, expected and predicted that Moore's Law will end by around 2025!!!

• The problem with the Moore's Law it's that, at current rate, the transistors will be as almost small as an atom, in ranges between 1 nanometer and 10 nanometers.

• If the scale of the transistors becomes too small, the Electrons randomly tunnel through micro-thin barriers (i.e., the commonly called gates), between wires.

• These micro-thin barriers or gates controls the flow of Electrons, shutting this electrical flow off and on, in a fraction of second.

• The Quantum Tunneling is more present at smaller distances, so at one point, it's not possible design and build smaller transistors without having randomly behaviours at the moment of, turning the electrical signal flow on or off.

• The problem it's that when the Electrons randomly tunnel through this gates, without any chance of shut off the electrical current, in randomly fashion, they corrupt the electrical signals flowing inside the transistors.

Computing Power and Speed

• It was proved that the power and speed of the computers increased exponentially, along the last years.

• Per example, the doubling time of computational capacity for personal computers was estimated as 1.5 years, between 1975 to 2009.

• It's reasonable to think that the number of Floating-Point Operations Carried Out Per Second (F.L.O.P.S.) by the largest supercomputers, in terms of computing power, also grown up exponentially.

• From it was witnessed a growth from 124 billion of Floating-Point Operations Carried Out Per Second (F.L.O.P.S.), in 1993, to 93,000 trillions of Floating-Point Operations Carried Out Per Second (F.L.O.P.S.), in 2017.

• The Microprocessors' Clock Speed, measured as the number of pulses per second (i.e., Hertz, a frequency unit), also grown up exponential, from 1.35 million Hertz to 28.75 billion Hertz, between 1976 and 2016.

Computing Efficiency

• Obviously, to keep such computing power, it's strictly necessary to be considered the cost aggregated to that.

• The electrical efficiency measures the Computational Capacity per Unit of Energy, and the associated energy production also have environmental impact.

• This electrical efficiency is measured as the number of Watts (i.e., a electrical and power unit) needed to carry out a Million Instructions Per Second (M.I.P.S.). This measurements are made by Watts per Million Instructions Per Second (M.I.P.S.).

• The Koomey's Law showed that in the last 60 years, the requirement and need of energy (i.e., amount of battery) for a fixed Computational Load declined by half every 18 months, in an inverse growth fashion.

• After 2000, the rate of this double decline trend, slowed down from occurring for every 18 months to occurring every 31 months.

• This new paradigm can be explained by the slowing rate of Moore's Law!!!

The transistors can be basically classified into two types:

• Bipolar Junction Transistors (B.J.T.s):

  • Three Terminals:

    • Emitter (E);

    • Base (B);

    • Collector (C);

  
  

  • Two Junction Types:

    • P-Type Semiconductors;

    • N-Type Semiconductors;

  
  

  • Electrical current-controlled devices;

  • Small amounts of electrical current flows through the base of a B.J.T. transistor, causing to flow large electrical current from emitter to collector;

  • Low input impedance, which causes flow large current through the transistor;

  • Turned on by the input electrical current, which is given to the base;

  
  

  • Operate in three regions:

  • Cut-off Region - The transistor is fully 'OFF' state (with the electrical current being zero);

  • Active Region - The transistor acts as an closed amplifier;

  • Saturation Region - The transistor is in fully 'ON' state and also works as a closed switch (with the electrical current being one);