Noise in Landau–Zener transition

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In summary, the study of noise in Landau–Zener transitions investigates how external perturbations, such as thermal or quantum fluctuations, affect the probability of system transitions between energy states in a time-dependent Hamiltonian. The presence of noise can lead to non-ideal transition probabilities, altering the expected outcomes of the transitions. This research is significant for understanding quantum control and coherence in various physical systems, with implications for quantum computing and information processing.
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Hello! I want to simulate a 2 level system in which the 2 levels are connected by an off-diagonal Hamiltonian term. I can linearly tune the distance between the 2 levels and thus I can transfer population from one to the other using a Landau–Zener transition. However, I want to add noise to this linear sweep. In my case the splitting between the 2 levels is adjusted by changing a magnetic field, but in practice the value of the magnetic field has some noise associated to it (due to noise in the current in the coils used to produce the magnetic field). I want to emphasize that that the noise leads to (small) changes in the magnetic while I do the linear sweep. So not only that the magnetic field is slightly different between different experimental runs, but it varies as a function of time while I perform the sweep. I would like to model this numerically and see the effect of different kind noise amplitude but I am not sure how to start. What is the easiest way to model noise in general and how should I proceed for more realistic representations of noise (any paper/book about this would be really appreciated, too)? In the end I would like to solve the Schrodinger equation associated to this 2x2 system in the presence of noise and extract the transition probability. Thank you!
 

FAQ: Noise in Landau–Zener transition

What is the Landau-Zener transition?

The Landau-Zener transition is a quantum mechanical model that describes the behavior of a two-level quantum system when subjected to a time-dependent perturbation. It focuses on the probability of a system transitioning from one energy state to another as an external parameter, such as an electric or magnetic field, is varied linearly with time.

How does noise affect the Landau-Zener transition?

Noise can significantly influence the probability of transition between energy states in the Landau-Zener model. It can either enhance or suppress the transition probabilities depending on the nature and characteristics of the noise. Noise introduces fluctuations that can alter the adiabaticity of the transition, leading to deviations from the idealized behavior predicted by the Landau-Zener formula.

What types of noise are commonly studied in the context of Landau-Zener transitions?

Common types of noise studied include white noise, which has a constant power spectral density, and colored noise, which has a frequency-dependent power spectral density. Examples of colored noise include 1/f noise and Ornstein-Uhlenbeck noise. Each type of noise can have different effects on the transition dynamics and probabilities.

Can noise be used to control Landau-Zener transitions?

Yes, noise can be used as a tool to control Landau-Zener transitions. By carefully engineering the noise characteristics, such as its amplitude and correlation time, it is possible to influence the transition probabilities in a desired manner. This technique can be useful in quantum computing and other applications where precise control over quantum state transitions is required.

What experimental systems are used to study noise in Landau-Zener transitions?

Experimental systems used to study noise in Landau-Zener transitions include superconducting qubits, trapped ions, quantum dots, and ultracold atoms. These systems allow for precise control and measurement of quantum states, making them ideal platforms for investigating the effects of noise on quantum transitions.

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