Quantum metamaterials

Quantum mechanics
Uncertainty principle
Introduction Glossary History
Background Classical mechanics Old quantum theory Bra–ket notation Hamiltonian Interference
Fundamentals Complementarity Decoherence Entanglement Energy level Measurement Nonlocality Quantum number State Superposition Symmetry Tunnelling Uncertainty Wave function (collapse)
Experiments Afshar Bell's inequality Davisson–Germer Double-slit Elitzur–Vaidman Franck–Hertz Mach–Zehnder Popper Quantum eraser (delayed-choice) Schrödinger's cat Stern–Gerlach Wheeler's delayed-choice
Formulations Overview Heisenberg Interaction Matrix Phase-space Schrödinger Sum-over-histories (path integral)
Equations Dirac Klein–Gordon Pauli Rydberg Schrödinger
Interpretations Overview Bayesian Consistent histories Copenhagen de Broglie–Bohm Ensemble Hidden-variable Many-worlds Objective collapse Quantum logic Relational Stochastic Transactional
Advanced topics Quantum chaos Quantum computing Density matrix Quantum field theory Fractional quantum mechanics Quantum information science Relativistic quantum mechanics Scattering theory Quantum statistical mechanics
Scientists Aharonov Bell Blackett Bloch Bohm Bohr Born Bose de Broglie Candlin Compton Dirac Davisson Debye Ehrenfest Einstein Everett Fock Fermi Feynman Glauber Gutzwiller Heisenberg Hilbert Jordan Kramers Pauli Lamb Landau Laue Moseley Millikan Onnes Planck Rabi Raman Rydberg Schrödinger Sommerfeld von Neumann Weyl Wien Wigner Zeeman Zeilinger

Quantum metamaterials extend the science of metamaterials to the quantum level. They can control electromagnetic radiation by applying the rules of quantum mechanics. In the broad sense, a quantum metamaterial is a metamaterial in which certain quantum properties of the medium must be taken into account and whose behaviour is thus described by both Maxwell's equations and the Schrödinger equation. Its behaviour reflects the existence of both EM waves and matter waves. The constituents can be at nanoscopic or microscopic scales, depending on the frequency range (e.g., optical or microwave).^{[1] [2] [3][4][5]}

In a more strict approach, a quantum metamaterial should demonstrate coherent quantum dynamics. Such a system is essentially a spatially extended controllable quantum object that allows additional ways of controlling the propagation of electromagnetic waves.^[2][3][4][5]

Quantum metamaterials can be narrowly defined as optical media that:^[6]

• Are composed of quantum coherent unit elements with engineered parameters;
• Exhibit controllable quantum states of these elements;
• Maintain quantum coherence for longer than the traversal time of a relevant electromagnetic signal.^[6][7]

Research

Fundamental research in quantum metamaterials creates opportunities for novel investigations in quantum phase transition, new perspectives on adiabatic quantum computation and a route to other quantum technology applications. Such a system is essentially a spatially-extended controllable quantum object that allows additional ways of controlling electromagnetic wave propagation.^[6]

In other words, quantum metamaterials incorporate quantum coherent states in order to control and manipulate electromagnetic radiation. With these materials, quantum information processing is combined with the science of metamaterials (periodic artificial electromagnetic materials). The unit cells can be imagined to function as qubits that maintain quantum coherence "long enough for the electromagnetic pulse to travel across". The quantum state is achieved through the material's individual cells. As each cell interacts with the propagating electromagnetic pulse, the whole system retains quantum coherence.^[6]

Several types of metamaterials are being studied. Nanowires can use quantum dots as the unit cells or artificial atoms of the structure, arranged as periodic nanostructures. This material demonstrates a negative index of refraction and effective magnetism and is simple to build. The radiated wavelength of interest is much larger than the constituent diameter. Another type uses periodically arranged cold atom cells, accomplished with ultra-cold gasses. A photonic bandgap can be demonstrated with this structure, along with tunability and control as a quantum system.^[3] Quantum metamaterial prototypes based on superconducting devices with ^{[8] [9]} and without ^[10] Josephson junctions are being actively investigated. Recently a superconducting quantum metamaterial prototype based on flux qubits was realized.^[11]

See also

• Negative index metamaterials
• Introduction to quantum mechanics
• Nanotechnology
• History of metamaterials

References

External links

• META 12. Special Sessions.
• Conference on Quantum Metamaterials
• Quantum metamaterials Imperial college London
• Quantum metamaterials SPIE
• A.M. Zagoskin. Loughborough University