It's clear from foundational research that qudits can provide an enhanced control of the Hilbert space over qubits, and I've encountered references that highlight improved [robustness and noise tolerance](https://journals.aps.org/pra/abstract/10.1103/PhysRevA.67.012311) in quantum protocols such as QKD when using higher-dimensional systems. Furthermore, the number of controlled-sign gates needed to implement a Toffoli gate can be reduced when using qudits (as illustrated with qutrits, in [this paper](https://journals.aps.org/pra/abstract/10.1103/PhysRevA.75.022313)). This could hint at a more efficient circuit design or even improved error correction capabilities with qudits. Yet, it's also understood that active error correction might not be a primary focus [for NISQ devices](https://quantum-journal.org/papers/q-2018-08-06-79/) due to the limited number of qubits available.

However, while the theoretical advantages are insightful, I'm curious about the potential  implications and possible benefits when integrating qudits into NISQ devices. Additionally, given that institutions like Fermilab are actively researching or even building qudit-based hardware (as detailed in this [Snowmass paper](https://arxiv.org/pdf/2204.08605.pdf)), there seems to be at least some practical interest in their potential in the NISQ era.

##### Decoherence and Noise
Are there any indications or studies suggesting that qudits might exhibit inherent advantages in terms of reduced decoherence or susceptibility to certain types of noise on NISQ devices, beyond the specific context of QKD?

##### Quantum Simulation
One of the promising applications of NISQ devices lies in their potential for [quantum simulation](https://www.nature.com/articles/s41586-022-04940-6). With qudits' richer state space, is there any evidence to suggest they might facilitate improved or more efficient quantum simulations of complex systems?

##### Hardware Considerations
I'm aware that creating and manipulating qudits tends to be more challenging than qubits. But is there any existing or emerging hardware architecture where qudits might have an experimental edge, or perhaps a unique synergy, when implemented on NISQ devices?

While a previous discussion on [Physics Stack Exchange](https://physics.stackexchange.com/questions/106325/advantage-of-taking-qutrits-in-place-of-qubits) touched upon some benefits of qudits, I'm particularly interested in their integration and potential benefits within the NISQ regime, given the practical challenges and opportunities it presents.