Physics

What the environment knows about your system, and how to make it confess. Derives the mean-force Hamiltonian directly from the influence functional — a cleaner account of what the bath has been doing to you all along.

There are no free lunches in complexity theory. This paper finds the complimentary buffet. Explores how certain quantum systems offer computational shortcuts that classical intuition insists shouldn't be there.

It turns out you do not need much of a quantum computer to compute quantumly. A considerable relief to everyone's grant applications. Shows that small, carefully encoded reservoirs punch well above their Hilbert space weight.

More expressivity squeezed from a photonic reservoir via the elegant application of slightly more mathematics. The word "unwrapping" is doing real work in the title.

Cramming a Bose-Einstein condensate into a space smaller than the wavelength of the light used to trap it. Remarkably tight parking, even by the standards of quantum optics.

A textbook. The authors are aware of how this looks. Written with the conviction that the best pedagogical texts are the ones that admit when something is genuinely strange.

Simulating imaginary time evolution on a quantum computer. A clever piece of accountancy that allows unitary devices to emulate non-unitary dynamics, provided you are willing to evolve things forwards and backwards. Useful for when your quantum computer refuses to break the rules.

A hundred-fold improvement in spectroscopic contrast. The press release writes itself; we resisted. The mechanism is superoscillation — making waves do things that the Fourier transform would prefer they didn't.

A band-limited wave can oscillate faster than its fastest Fourier component. We made this useful. Proof that physics occasionally rewards those who insist on doing what is formally impossible.

Quantum mechanics and classical mechanics share more furniture than you would think. This paper draws the floor plan — a unified operator framework that makes the analogy precise and, on a good day, useful.

An argument that a single atom, correctly interrogated via high-harmonic generation, is a computer. Impractical. Energetically dubious. Correct. The kind of paper that exists to prove a point about what the universe permits.

Making a material electromagnetically near-invisible, without touching the material. Epsilon-near-zero behaviour engineered entirely through feedback control. The conjuror's version of materials science.

Turns out there are many ways to skin a photon. Different laser fields can produce identical optical responses — which is either a headache for experimentalists or an opportunity for theorists. We chose the latter framing.

An identity parade for strongly correlated materials. Can light tell a Mott insulator from its neighbours, and does it matter whether you ask in the time or frequency domain? Mostly yes, and yes.

Characterising a chemical mixture by selectively silencing its components — one at a time, in sequence. A very polite form of interrogation. Works by making each constituent optically invisible until only the one you want can be heard.

The free particle and the harmonic oscillator are, in a meaningful sense, the same system wearing different hats. This paper documents the wardrobe. Extends to the Koopman setting, where classical mechanics gets the same treatment.

Two entirely different materials, made to look identical to every optical measurement you can perform. A physics magic trick — the mechanism is real, the implications for spectroscopy are uncomfortable, and the result is PRL.

A rank truncation scheme for simulating open quantum systems. Faster. Less exact. Entirely honest about that trade-off in the abstract, which is more than can be said for most approximations in the literature.

A title that has done more editorial work than any abstract I have written. The paper itself derives stochastic equations from deterministic dynamics. The title got us into the journal. I stand by both.

On whether simple diffusion can explain olfaction. It cannot — the nose is a more mysterious instrument than that. One a of a small number of my publications to have generated genuine dinner-table conversation.

A proposal to test whether gravity is fundamentally quantum mechanical — engineered so that quantum decoherence cannot muddy the result. Gravity, it turns out, is already under enough suspicion without giving it alibis.

Turning water into wine — demonstrating that laser pulses can force one quantum material to impersonate another with perfect fidelity. The Bible describes the miracle; this paper explains the mechanism. First runner-up in the competition for most satisfying result of my career so far.

The full theoretical machinery behind Driven Imposters — the technical rider to the conjuring trick. If the PRL was the headline act, this is the tour bus, the crew, and everything that made the thing work.

The second law of thermodynamics is famously robust. The boundary conditions of Hamiltonian mechanics are, it transpires, less so. A careful look at the seams of classical statistical mechanics.

The magnum opus of a graduate student. Several hundred pages on exact stochastic methods for open quantum systems. Approximately one person has read it cover to cover; that person was a referee, and I am grateful for their fortitude.

The second paper. Things were still relatively tidy; the abstracts had not yet developed opinions about themselves. A rigorous treatment of driven spin-boson dynamics that set the tone for most of what followed.

Where it all began. The first paper — on exact stochastic equations for open quantum systems without the usual approximation-before-you-start. Read with appropriate historical sympathy; the author was twenty-four and had not yet developed strong feelings about boundary conditions.