Related Experiment Video
Updated: Apr 11, 2026
12:57
Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
9.7K
Electron spin coherence near room temperature in magnetic quantum dots
Fabrizio Moro1, Lyudmila Turyanska1, James Wilman1
1School of Physics and Astronomy, The University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Scientific Reports
|June 5, 2015
Summary
Researchers confined single manganese (Mn2+) spins in semiconductor quantum dots (QDs) within a proton-free matrix. This achieved long electron spin coherence near room temperature, crucial for quantum technologies.
Area of Science:
- Materials Science
- Quantum Physics
- Nanotechnology
Background:
- Controlling magnetic ions at the nanoscale is key for quantum information processing.
- Achieving long spin coherence times, especially near room temperature, remains a significant challenge.
Purpose of the Study:
- To demonstrate long spin coherence of confined magnetic ions near room temperature.
- To investigate the effect of confinement and matrix environment on spin dynamics of Mn(2+) ions.
Main Methods:
- Confining single manganese (Mn2+) spins within colloidal semiconductor quantum dots (QDs).
- Dispersing the quantum dots in a proton-spin free matrix to minimize environmental noise.
- Utilizing techniques to suppress Mn-Mn and Mn-nuclear spin interactions.
Main Results:
- Achieved unprecedentedly long phase memory (TM ~ 8 μs) and spin-lattice relaxation (T1 ~ 10 ms) for Mn(2+) ions at 4.5 K.
- Observed electron spin coherence near room temperature with TM ~ 1 μs.
- Demonstrated controlled suppression of magnetic ion interactions.
Conclusions:
- Confining single Mn(2+) spins in semiconductor QDs within a proton-spin free matrix enables long spin coherence near room temperature.
- This approach offers a promising pathway for developing robust quantum bits (qubits) and quantum sensors.
- The findings highlight the potential of engineered nanomaterials for advanced quantum applications.
Related Concept Videos
01:03Atomic Nuclei: Nuclear Spin State Overview
2.3K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
2.3K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
2.6K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
2.6K
01:08NMR Spectroscopy: Spin–Spin Coupling
3.8K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
3.8K
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.4K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.4K
01:23Magnetic Moment of an Electron
3.4K
Electrons revolving around a nucleus are analogous to a circular current carrying loop. This current produces a magnetic dipole moment proportional to the electron's orbital angular momentum. Since the orbital angular momentum is quantized in terms of the reduced Planck's constant, the dipole moment is quantized in the Bohr Magneton. The value of the Bohr magneton is 9.27 x 10-24 Am2. Electrons also have an intrinsic spin angular momentum, and the associated spin magnetic moment is...
3.4K
03:06The Pauli Exclusion Principle
61.9K
The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:
61.9K