Jahan Claes

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Periodic vs Open boundary conditions

quantum-mechanics condensed-matter boundary-conditions asked Apr 5, 2017 at 22:54

physics.stackexchange.com

24 votes

Mean field equations in the BCS theory of superconductivity

quantum-mechanics condensed-matter superconductivity asked Jan 20, 2017 at 21:28

physics.stackexchange.com

22 votes

Quantizing a complex Klein-Gordon Field: Why are there two types of excitations?

quantum-field-theory commutator complex-numbers second-quantization klein-gordon-equation asked Nov 26, 2016 at 15:19

physics.stackexchange.com

13 votes

Why can't the $\mathbb{Z}_2$ invariant be defined with a determinant instead of a pfaffian?

condensed-matter topological-insulators asked Jan 25, 2019 at 1:23

physics.stackexchange.com

9 votes

Computing the density operator commutation relations (Altland & Simons)

quantum-mechanics condensed-matter commutator density-operator second-quantization asked May 27, 2016 at 15:35

physics.stackexchange.com

8 votes

Is there a convention for denoting $Y$ eigenstates?

quantum-state pauli-gates notation asked Aug 26, 2021 at 19:18

quantumcomputing.stackexchange.com

7 votes

How is it possible to initialize a quantum state in a superposition of energy eigenstates?

quantum-mechanics energy-conservation conservation-laws asked Mar 18, 2022 at 17:59

physics.stackexchange.com

6 votes

Second Quantization: Do fermion operators on different sites HAVE to anticommute?

fermions commutator second-quantization anticommutator asked Jun 17, 2016 at 18:55

physics.stackexchange.com

6 votes

Irreducible representations of $SO(N)$

representation-theory orthogonal-matrices asked Sep 21, 2020 at 18:34

math.stackexchange.com

6 votes

Finding the minimum degree of a representation of an algebra

abstract-algebra group-theory representation-theory asked Sep 5, 2018 at 1:05

math.stackexchange.com

Top Answers

Energy Conservation Dilemma

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Can Second Law of Thermodynamics / Entropy override Newton's Laws?

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Is it insider trading to purchase shares in a competitor?

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How to deal with zero uncertainties?

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Why aren't interactions between molecules of an ideal gas and walls of container negligible?

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Are all Lagrangians translationally invariant?

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Undefined Hamiltonian for this particular Lagrangian

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Why is this true for matrices? Linearly dependent columns $\implies$ not invertible

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How did physicists know that only negative charges move?

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Shouldn't the Uncertainty Principle be intuitively obvious, at least when talking about the position and momentum of an object?

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Why the Lagrangian $L$ is KE - PE? Why not KE + PE!

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Does Robert Wald's definition of a manifold make it a topological space?

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Griffith's Proof that a wave function will stay normalized is incorrect?

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Show That There Is One and (Essentially) Only One Field With 3 Elements

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Speed of Dark experiment, does it *really* travel faster than light?

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How to find Hamiltonian from this simple Lagrangian? (tricky)

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Why is the Berry curvature odd under time reversal?

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Simple Pendulum Why Generalized Coordinate Always Angle?

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Dirac Delta function inverse Fourier transform

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Bound states of the $V(x)=\pm \delta'^{(n)}(x)$ potential?

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Wave packet expression and Fourier transforms

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Heisenberg uncertainty principle and zero point energy

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Book recommendations - Topological Insulators for dummies

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Why does Melosh not consider the term $\vec{v}\frac{dm}{dt}$ in Newton's second law for a meteorite that loses mass by ablation?

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Is a quadratic Majorana Hamiltonian exactly solvable?

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Why are POVMs useful? Are they just an axiomatic way to define measurement?

quantumcomputing.stackexchange.com

How did Wolverine get his Adamantium back between X-Men Annual Vol. 1 #11 and 12?

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Is the plus state a magic state for the Hadamard gate?

quantumcomputing.stackexchange.com

Why do cross products not change their sign under an inversion of coordinates?

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Existence and Uniqueness of Newton's Laws

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