[ad_1]
Army scientists predicted that quantum computer circuits that will no longer need extremely cold temperatures to function could soon become available.
Scientists have demonstrated the feasibility of a quantum logic gate composed of photonic circuits and optical crystals.
One of the significant drawbacks of quantum systems is the fragility of the strange states of the qubits. Most of the impending hardware for quantum technology must be kept in very cold temperatures, near zero degrees Kelvin, to avoid the extraordinary states that are pulverized by associating with the computer environment.
Dr. Kurt Jacobs of the Army Research Laboratory of the US Army Combat Capability Development Command. USA said: “Any interaction you have a qubit with anything else in your environment will start to distort your quantum state. For example, if the environment is a particulate gas, keeping it very cold causes the gas molecules to move slowly, so they don’t collide as much in quantum circuits. “
Scientists led various efforts to solve this problem, but a definitive solution has yet to be found. At the moment, photonic circuits incorporating nonlinear optical crystals have now emerged as the only viable route for quantum computing with solid-state systems at room temperature.
Unlike quantum systems that use ions or toms to store data, quantum systems that use photons can avoid cold temperature limitation. However, photons should even interact with different photons to perform logical operations. This is the place where nonlinear optical crystals become an integral factor.
Scientists can design cavities in crystals that temporarily trap photons inside them. In doing so, the quantum system can establish two different possible states that a qubit can contain: a cavity with a photon (on) and a cavity without a photon (off). These qubits can form quantum logic gates, which create the framework for strange states.
Meanwhile, scientists can use the undetermined state of whether or not a photon is in a crystal cavity to represent a qubit.
Logic gates act on two qubits together and can create a “quantum entanglement” between them. This tangle is automatically generated on a quantum computer and is required for quantum approaches to detection applications.
However, the idea of making quantum logic gates using nonlinear optical crystals remains a hypothesis. There are still questions about whether this could lead to practical logic gates.
Now, Army scientists, in collaboration with MIT, have presented a new way to realize a quantum logic gate with this approach using established photonic circuit components.
Jacobs said: “The problem was that if you have a photon traveling on a channel, the photon has a ‘wave packet’ of a certain shape. For a quantum gate, you need the photon wave packets to stay the same after the operation of the gate. Since nonlinearities distort wave packets, the question was whether you could load the wave packet into the cavities, make them interact through a non-linearity, and then emit the photons again so they have the same wave packets that they started with. “
Scientists noted, “Once they designed the quantum logic gate, the researchers performed numerous computer simulations of the gate’s operation to demonstrate that, in theory, it could work properly. The actual construction of a quantum logic gate with this method will first require significant improvements in the quality of certain photonic components. “
Dr. Mikkel Heuck of the Massachusetts Institute of Technology said: “Based on the progress made in the last decade, we hope it will take around ten years for the necessary improvements to be made. However, the process of loading and outputting a wave packet without distortion is something we should be able to do with current experimental technology. So that’s an experiment we’ll work on next. “
Magazine reference:
- Mikkel Heuck, phase controlled gate using dynamically coupled cavities and optical nonlinearities. DOI: 10.1103 / PhysRevLett.124.160501
