Third sound detectors in accelerated motion

Abstract

Using a laser as a local detector of superfluid helium-4 surface modes, known as third sound waves, we propose an experiment to probe observer-dependence in detector response. By moving the interaction point along a circular trajectory, the response can be compared with its inertial counterpart. Disagreement between the two is a manifestation of the Unruh effect, predicting that the uniformly accelerated observer will experience a temperature in empty space. Third sound waves propagate in an effective spacetime, wherein the effect of acceleration is enhanced. Incorporating a nonzero ambient temperature, we identify an acceleration-dependent signal in the laser phase, and evaluate a signal-to-noise measure to show that observing this signal is within experimental reach.

Non-linear effective field theory simulators in two-fluid interfaces

“…We presented in this Proceeding a detailed derivation of an effective field theory for the nonlinear dynamics of interfacial waves between two fluids based on prior work on fluid dynamics [15,20]. By focusing on specific approximate cases, we reviewed previous linear simulators for flat and inflationary spacetimes as in [6] and [26], and built-up a framework that can be used to investigate interacting field theories. In the latter case, we exemplified this by simulating the nonlinear onset and subsequent particle decay of reheating in inflationary cosmology, in line with [14].…”

“…Notable examples include measurements of analogue Hawking radiation [37] around various effective horizons [7,8,10,38], and analogue black hole phenomena in dispersive draining vortex flows [11,12]. Building on the firm foundations laid by these previous simulators, recent developments are motivating and driving the extension of the underlying quantum field theories [26,14,23,6], fostering a symbiosis between experiment and theory within analogue gravity. This definition indicates that D j is an asymmetric, dimensionless, square matrix.…”

“…In the limit ρ 1 ≫ ρ 2 , the Atwood number A tends to unity, and the resulting equation represents the effective field theory for surface modes in an inviscid fluid. This correspondence is of particular relevance for creating gravity simulators of quantum processes that can take place on flat spacetime, such as the Unruh effect [22], as proposed in [23,6] on the interface of superfluid helium.…”

“…Over four decades ago, William Unruh demonstrated that the arguments leading to Hawking radiation also predict a thermal spectrum of sound waves from the sonic horizon in transonic fluid flows [1], from which arose analogue gravity. This field now resonates with several areas throughout physics [2,3], with experimental and theoretical efforts in ultracold atoms systems [4,5], superfluids [6], and optical systems [7,8]. Many of these gravity simulators rely on mathematical equivalences between the dynamical equations of quantum fields in curved spacetimes and an Effective Field Theory (EFT) emerging from the underlying physical description of the simulator at hand.…”

Circular motion analogue Unruh effect in a 2+1 thermal bath: robbing from the rich and giving to the poor

“…Phenomena similar to the Unruh effect exist also for non-linear uniform motion [8][9][10], including uniform circular motion [11][12][13][14][15]. Experimental interest in the circular motion Unruh effect has a long standing [16][17][18][19][20][21][22], in which a new angle was opened by recent proposals [23][24][25][26] to utilise the analogue spacetime that occurs in nonrelativistic laboratory systems [27][28][29].…”