Published - 28 July 2020

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Quantum Computing can be simply defined as "Use of quantum effects to store and compute data". Quantum computing is emerging as a gamechanger in today's computer industry.

But what is the need of quantum computing? Today we use semiconductor technology for computers. By increasing the number of transistors in a given area we are increasing the capacity of data storage. But we can't keep on reducing the size of transistors. There is a limit to it. The advantages of small size are:

• Less heat generation
• Less inertia
• More capacity in a given area

If we are able to store 1 bit using the size of an atom or even less than that, we can achieve the above-mentioned advantages. But at this size, quantum effects like quantum entanglement and superposition come into the picture. What if we can utilize this quantum phenomenon to store the bit? Quantum computing does exactly that. This bit is called a qubit in the quantum computing world.

Qubit is the centre of attraction of quantum computing. As the number of coherent yet completely isolated qubits rise, the capacity of a quantum computer increases. But implementing a large number of qubits together makes it difficult to achieve coherence.

Qubits can be encoded using quantum phenomena. There are 4 types of qubits depending on the phenomenon used to create them. Those are spin qubits, NV centre qubits, superconducting qubits, and topological qubits. Each has its advantages and disadvantages.

In classical computing, some problems are believed to be intractable. Using quantum algorithms for the same problems makes them tractable. The meaning of intractability of a problem is "The problem can be solved but it can take decades or even time equal to the age of the universe to solve the problem using a classical computer. A quantum computer is essentially a quantum accelerator. It speeds up the tasks of a classical computer. As we use FPGA and/or GPU with a classical CPU, we can use a quantum accelerator chip with a classical CPU. Some tasks which cannot be done instantly on a CPU can be executed instantly on a quantum accelerator. The CPU can perform its usual tasks and only such intractable problems can be handed over to the quantum accelerator.

An example of such a problem is "factoring" which is used by RSA (RSA: Rivest–Shamir–Adleman is one of the first public-key cryptosystems and is widely used for secure data transmission) as it is believed to be intractable. But using Shor's quantum algorithm this problem becomes tractable. As RSA is used by many networking protocols for security, all these protocols will become insecure if this algorithm is implemented easily and economically.

As the field of quantum computing is still in its infancy, there is very little research in this area which has led to fewer patents. As developing a quantum computer is expensive, access to this technology is limited to billion-dollar companies like Google. Google has many patents in this area. E.g. "Chips including classical and quantum computing processors". Google has also developed its own quantum computer.

One of the many fields in quantum computing in which there is a huge possibility for patents is quantum cryptography. Classical cryptography uses intractable problems to provide data encryption services. Using quantum algorithms, many of these problems become tractable and classical cryptography becomes insecure. The need for Quantum Cryptography arises from this problem. Quantum cryptography can re-establish the security which was previously provided by classical cryptography. One such patent by Hewlett Packard Enterprise Development LP in 2004 describes "A method of establishing a shared secret random cryptographic key between a sender and a recipient using a quantum communications channel". BT Group, a British multinational telecommunications company, United Kingdom, has filed over 100 patents in quantum cryptography.

Quantum algorithms can be developed using a mathematical model of quantum computing, which eliminates the need for actual hardware for quantum computing research. Patents can be acquired for quantum algorithms based on mathematical models, bypassing the need for extremely expensive quantum hardware. The mathematical model of quantum computing uses:

• Linear Algebra - Specifically vector space
• Hilbert space
• Classical computing

The mathematical model abstracts the quantum effects, which makes it easy to create and prove quantum algorithms.

In 2018, China had nearly twice as many patent filings as the United States for quantum technology overall, a category that includes communications and cryptology devices. The US, though, leads the world in patents relating to the most prized segment of the field -quantum computers- thanks to heavy investment by IBM, Google, Microsoft, and others. Most of the patents pertain to the physical platforms used to implement the qubit, such as superconducting circuits, semiconductor materials, ion traps, quantum dots, color centers in diamond, topological devices. However, there is a huge scope of research in quantum cryptography and mathematical models and quantum algorithms in quantum computing which does not require a million-dollar hardware.

Most of the patents pertain to the physical platforms used to implement the qubit, such as superconducting circuits, semiconductor materials, ion traps, quantum dots, color centers in diamond, topological devices. However, there is a huge scope of research in quantum cryptography and mathematical models and quantum algorithms in quantum computing which does not require a million-dollar hardware.