Related Experiment Video
Updated: Jul 2, 2025
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
7.5K
Qubit gate operations in elliptically trapped polariton condensates.
Luciano S Ricco1, Ivan A Shelykh2,3,4, Alexey Kavokin5,6,7
1Science Institute, University of Iceland, Dunhagi-3, IS-107, Reykjavik, Iceland. lsricco@hi.is.
Scientific Reports
|February 21, 2024
Summary
Researchers developed optical quantum gates for exciton-polariton condensates in elliptical traps. This work enables quantum computing with polariton qubits, paving the way for novel quantum algorithms.
Area of Science:
- Quantum physics
- Condensed matter physics
- Optics
Background:
- Exciton-polaritons are quasiparticles formed from excitons and photons.
- Quantum computing requires robust qubits and quantum gates.
Purpose of the Study:
- To propose and analyze a system of optically tunable qubits based on exciton-polariton condensates.
- To design universal single- and two-qubit gates for quantum information processing.
- To investigate the impact of decoherence mechanisms on qubit fidelity.
Main Methods:
- Utilizing bosonic condensates of exciton-polaritons confined in elliptical traps.
- Representing qubit states on a Bloch sphere using superpositions of p-type states.
- Employing auxiliary laser beams for single-qubit gate operations.
- Investigating inter-trap interactions for two-qubit gate implementation (CPHASE, CNOT).
- Analyzing error sources like pure dephasing and spontaneous relaxation.
Main Results:
- Demonstrated a method for creating optically tunable qubits from exciton-polariton condensates.
- Developed universal single-qubit gates and two-qubit gates (CPHASE, CNOT).
- Quantified the fidelity reduction and increased entropy due to decoherence.
- Assessed the proposal against DiVincenzo's criteria for quantum computation.
Conclusions:
- The proposed system offers a promising platform for quantum information processing using polariton qubits.
- Optically controlled quantum gates can be realized in planar microcavities with elliptical traps.
- This research lays the groundwork for implementing quantum algorithms with polariton-based quantum computers.
Related Concept Videos
01:29Potential Due to a Polarized Object
403
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
403
01:03Atomic Nuclei: Nuclear Spin State Overview
946
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...
946
03:06The Pauli Exclusion Principle
37.2K
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:
37.2K
01:23Atomic Nuclei: Nuclear Relaxation Processes
654
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.
654
01:28Induced Electric Dipoles
4.2K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.2K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
981
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.
981