Shane Wilson's Blog

Could Quantum be the next big wave in VC investing?  This is a question I’ve explored over the last 6 months.  Having attended a few industry talks, understanding this sector requires a base vocabulary of topics and concepts that are esoteric to the uninitiated.  And fair warning- initiation ≠ understanding in this context.  Definitions and analogies provide some illumination, but truly understanding these concepts probably requires a PhD.  For my purposes, I really am just looking for a conversational understanding that will allow me to follow along when people start to explain these things 

I grabbed the transcripts and my notes from a few live events in the Spring of 2025.  Then, I chunked this file into ChatGPT to isolate key terms, provide definitions, and attempt useful analogies.  Warning: what follows is liable to include some AI slop.

1. Foundations of Quantum Physics

To understand quantum computing, the first order of business is gaining a conversational understanding of Quantum Physics.  With these concepts under your belt, you can build towards understanding Quantum Computing and its applications. 

Term	Definition	Analogy
superposition	Superposition is a quantum phenomenon where a qubit exists in a combination of multiple states simultaneously (e.g., 0 and 1 at the same time), enabling quantum computers to process a vast number of possibilities concurrently.	Like being in multiple places at once until someone checks where you really are.
entanglement	Entanglement is a quantum property where two or more qubits become linked such that the state of one instantly influences the state of the other, no matter how far apart they are. This is crucial for quantum communication and computation.	Like a pair of dice that always roll matching numbers, even if they‚ are on opposite sides of the world.
interference	Interference in quantum computing refers to the way quantum states combine, amplifying the probability of correct outcomes and canceling out incorrect ones. It is harnessed in algorithms to guide the computation toward valid answers.	Like ripples in a pond overlapping to form a bigger wave or cancel each other out.
Hamiltonian	A Hamiltonian is a mathematical expression used to describe the total energy of a quantum system. In quantum computing, it guides how a system evolves over time and is central to quantum simulation and optimization problems.	Like a blueprint that tells particles how to move and interact.
decoherence and noise	Decoherence and noise are processes that disrupt quantum states by causing them to lose coherence and become entangled with their environment, leading to errors in computation.	Like trying to balance a pencil on its tip in a hurricane‚ it quickly falls over due to disturbances.

2. Core Concepts in Quantum Computing

Once you understand the physics, we can increase specificity with Quantum Computing basics.

Term	Definition	Analogy
Moore’s law	Moore’s law predicts that the number of transistors on a microchip doubles approximately every two years, leading to exponential increases in computing power. However, this trend is plateauing due to physical limitations, prompting exploration of quantum alternatives.	Like trying to cram more and more books into a shrinking bookshelf‚ eventually, you run out of space.
quantum computing	Quantum computing leverages the principles of quantum mechanics‚ specifically superposition, entanglement, and interference‚ to perform computations. Unlike classical computers that operate on bits, quantum computers use qubits, which can be in multiple states simultaneously. This allows them to explore many possibilities at once, offering exponential speed-ups for certain complex problems such as factoring large numbers, simulating quantum systems, and optimizing complex systems.	Like trying every combination on a lock at once instead of one at a time.
qubit	A qubit is the fundamental unit of quantum information. Unlike a classical bit, which can be either 0 or 1, a qubit can exist in a superposition of both states at the same time. When measured, it collapses to one of the two outcomes, but while unmeasured, it holds richer information.	Like a spinning coin showing both heads and tails until it lands.
fidelity	In quantum computing, fidelity refers to the accuracy of a quantum operation or the degree to which a quantum state or process matches the intended or ideal one. High fidelity is essential for reliable quantum computation.	Like how closely a recorded song matches the live performance‚ the clearer the match, the better the fidelity.
error-aware qubits	Error-aware qubits are qubits embedded with mechanisms to detect or log errors during computation. These allow systems to track, mitigate, or correct faults in real time, enhancing reliability.	Like a smoke detector that warns you before something burns instead of waiting for a fire.
error correction	Quantum error correction is a set of techniques to protect quantum information from errors due to decoherence and noise. It involves encoding logical qubits across many physical qubits and detecting/correcting errors without measuring the quantum data directly.	Like checking and fixing a paragraph of invisible ink without erasing the message underneath.
logical qubit	A logical qubit is an error-resistant representation of a qubit, constructed from multiple physical qubits. It behaves as a more stable and reliable unit of quantum information, essential for scalable quantum computing.	Like a team of scouts passing a message together to ensure it arrives intact.
scaling	Scaling in quantum computing refers to increasing the number of usable qubits and system complexity while maintaining performance and fidelity. True scaling is a major hurdle due to hardware constraints and error rates.	Like adding more instruments to an orchestra while keeping everyone perfectly in sync.

3. Hardware: Modalities and Physical Platforms

There’s no one way to build a quantum computer. Hardware platforms—called modalities—each have unique advantages and tradeoffs.

Term	Definition	Analogy
modalities	Modalities in quantum computing refer to different physical platforms used to build and control qubits, such as superconducting circuits, trapped ions, neutral atoms, or photonic systems. Each has trade-offs in speed, scalability, and error tolerance.	Like different languages for telling a story—each can express the same idea differently and with its own quirks.
superconducting circuits	Superconducting circuits are a quantum computing modality that uses zero-resistance electrical loops cooled to near absolute zero to create and manipulate qubits with high speed and coherence.	Like building logic gates out of lossless racetracks for electrons.
trapped ions	Trapped ions use charged atoms suspended in electromagnetic fields as qubits. They are manipulated using lasers and are known for their long coherence times and high fidelity operations.	Like holding fireflies perfectly still in midair and using light to make them blink in specific patterns.
neutral atoms	Neutral atoms are uncharged atoms arranged and controlled using lasers and optical tweezers to serve as qubits. They offer scalability and are naturally less sensitive to noise than charged particles.	Like arranging marbles with beams of light and using them to play a precise, silent symphony.
photonic systems	Photonic quantum systems use individual particles of light (photons) to carry and process quantum information. They are naturally immune to certain types of noise and ideal for communication.	Like using laser beams as couriers to carry secret messages instantly.
dilution refrigerators	Dilution refrigerators are specialized cryogenic devices used to cool quantum processors to temperatures near absolute zero, where qubits can maintain coherence and function correctly without thermal noise.	Like turning down the temperature so low that time almost freezes—ideal for delicate quantum experiments.

4. Software, Algorithms, and Quantum Logic

Quantum hardware is only useful if you can give it good instructions. The software stack is what bridges user intent with quantum execution.

Term	Definition	Analogy
parallel computing	Parallel computing is a classical strategy where a problem is divided into sub-tasks that are processed simultaneously using multiple processors. This approach improves speed but still requires deterministic paths to solutions.	Like multiple chefs in a kitchen each working on a different dish at the same time.
QPU	A Quantum Processing Unit (QPU) is the quantum counterpart to a classical CPU. It processes qubits and executes quantum algorithms. QPUs are often housed in specialized environments like dilution refrigerators to maintain the delicate quantum states needed for computation.	Like the engine of a quantum car, it’s what drives the computation forward.
algorithms	In quantum computing, algorithms are specially designed sets of instructions that exploit quantum phenomena to solve problems more efficiently than classical algorithms. Notable examples include Shor’s algorithm for factoring and Grover’s algorithm for search.	Like having a shortcut that leads you through a maze faster than walking every path.
center surface code	The surface code is a robust quantum error-correcting code that lays out qubits in a 2D grid. It enables detection and correction of multiple types of errors and is considered one of the most viable paths to fault-tolerant quantum computing.	Like a woven net that catches errors from multiple directions before they break the system.
physical qubits vs logical qubits	Physical qubits are the actual hardware units, while logical qubits are combinations of these that include error correction. You need many physical qubits to create one logical qubit that can be reliably used in algorithms.	Like using many bricks (physical) to build one secure wall (logical).

5. Quantum Applications and Applied Technologies

Now that you’ve built the machine and written your code, what can quantum actually do? These technologies are beginning to reshape sensing, communication, and computation.

Term	Definition	Analogy
quantum technologies	Quantum technologies include any technologies that utilize quantum mechanical effects. This broad category includes quantum computing, quantum sensing (e.g., precise magnetic field detectors), and quantum communication (e.g., quantum key distribution for secure messaging).	Like using the strange rules of the quantum world to build better tools and machines.
quantum sensing	Quantum sensing uses quantum properties like entanglement and superposition to achieve ultra-precise measurements of time, gravity, magnetic fields, and other physical phenomena.	Like upgrading your senses to superhero levels of precision.
quantum communication	Quantum communication uses quantum mechanics, particularly entanglement and quantum key distribution (QKD), to transmit information in a way that is inherently secure and impossible to intercept without detection.	Like sending messages with invisible ink that disappears if someone tries to read it.