#### Quantum Technologies

Quantum technologies in particular are at the spearhead of scientific research and technical development. The Ion Quantum Technology group in particular are in the process of researching. creating and developing novel quantum technologies which form the basis of quantum products that will be available in the future.

Some examples of possible products based on quantum technology which will be available in the future include quantum clocks, quantum communication, quantum simulation and finally quantum computing and information processing. The basis of these are explained below.

__Quantum Clocks__

Quantum clocks would be able to make clocks more accurate than atomic clocks that are available at the moment. These would be important especially in financial and commercial situations where even a fraction of a second could make a difference in transactions.

Quantum clocks could also be used in navigation and GPS where to provide and accurate position requires the syncing of clocks between satellites, computers, and networks. A quantum clock would mean that clocks can be synced to within nanoseconds providing increased accuracy due to higher data rates.

In research quantum clocks would allow more accurate and precise measurements in systems where time is a crucial component such as satellites and space systems, as well as experiments in which measurements have to be performed to fraction of a second timings.

__Quantum Communication__

Current encryption mechanisms rely on the secure sharing of keys to encrypt and decrypt information and communication, however given sufficient computational power these keys can be calculated leading to the decryption of sensitive or important communication channels (see Shor's Algorithm in the. Quantum Computing and Quantum Information section).

Quantum key distribution can create fully secure communications for any need. By utilising a quantum network to share keys an eavesdropper would be unable to decipher the communication do to the nature of quantum information and decoherence. Certain quantum key distribution systems are already in the market, however are still in their infancy,

Quantum networks can be created to share and transfer quantum information, for example by chaining quantum bits together over a distance to create a network. Quantum teleportation can also be used to transmit information about a qubit from one place to another without it being copied by using entangled qubits where manipulating one of the qubits will affect the other, even if they have been separated.

__Quantum Sensors__

Due to the precision of quantum devices and measurements, quantum sensors would be incredibly useful in defense, industry and healthcare. For example, quantum sensors would be used to study cell structure and chemical compounds in detail paving the way for improvements in healthcare due to new medicine being created and improving diagnoses for patients.

In many industries the sensitivity on sensors is key, quantum devices would improve the sensitivity of devices by many orders of magnitude, being able to detect minute differences in measurements. A quantum gravitational field detector would be able to detect changes in density in the structure of the Earth's crust for example to find untapped oil deposits.

The most prevalent use for gravitational sensors would be in security and defense, examples of uses include sensing and imaging through walls and objects to detect persons and materials, and being able to determine their positions and moments.

Similar sensors would also be used in architecture and structural engineering, being able to accurately determine the structure of the ground would allow for more stable and secure buildings, for example in locations with an affinity for earthquakes or flooding.

__Quantum Simulation__

Simulations of quantum systems would lead to a greater understanding of physics. A physical system and its dynamics can be described by mathematics. A few simple examples can be solved using pen and paper, but many real world problems are incredibly complex and require a computer to solve efficiently. Computers can perform thousands of mathematical operations per second, and therefore can solve complicated problems that would be impossible otherwise. Using a computer to solve maths that corresponds to a physical system is known as simulation.

There are a whole host of possible simulations that can be performed using trapped ions from all areas of physics, including effects of Einstein’s theory of special relativity, particle creation moments after the big bang and complex many-body phenomena such as quantum biology and quantum chemistry, all of which cannot be simulated on a classical computer. All of these examples provide unique research opportunities allowing trapped ion experiments to connect with problems from all areas of physics and science beyond.

In the IQT group at Sussex trapped ions are used as a controllable quantum system which can be used to simulate other quantum systems. For example a simulation class makes use of a micro-fabricated chip trap where the ions are trapped in a ring configuration and can be moved around in a circle. This structure allows for the quantum simulation of Hawking radiation. Originally proposed by Stephen Hawking, the theory predicts that radiation should be emitted from the event horizon of a black hole. However, this radiation has never been observed.

__Quantum Computing and Quantum Information __

There are a number of scientific applications for quantum computing. Among them include the analysis of "big data", which is any data set which is too large or complex to process through conventional means. However through the use of a quantum computer and certain quantum algorithms the time taken to compute large sets of data is exponentially reduced.

An example of an quantum algorithm which could be implemented in information processing is Grover's algorithm. This algorithm is designed for searching an unsorted database or a set size for a single entry. Currently the best way of searching through an unsorted database is to simply search through every entry until the one being searched for is found. However due to quantum effects Grover's algorithm would provide a quadratic speed up (to the order of the square root of the total number of entries) in the time it takes to find the entry.

Another quantum algorithm that would be important in the fields of security and communication is Shor's Algorithm, used to find the prime factors of an integer. If large scale quantum computer could be built then the algorithm could be used to break public-key cryptographic methods with relative ease. This includes the popular RSA method, which uses large prime numbers under the pretense that the factors cannot be easily computed, which is the case with current computation. However this has led to the development of schemes utilising quantum effects for encryption (quantum cryptography).

__Miscellaneous quantum technologies__

Research in quantum technologies goes hand in hand with other areas of science such as material science and nanoscale technology to develop new materials, systems, and devices down to the molecular level to improve efficiency, for example more efficiently designed electrical components such as resistors, capacitors, and transistors would reduce waste heat in devices using these components.

A quarter of a century ago it was inconceivable that we'd be able to carry around a fully fledged computer around in our pockets, the smartphone. In the same way there will be unique and novel uses for quantum technologies for which it is currently impossible to perceive, but will none the less come to be discovered over the coming years.