Some Highlights from Tolya’s Research

Solid State NMR

Anatoly developed more efficient sequences for heteronuclear broadband decoupling, such as SPINAL, CPM mn, and nPPM.

13C spectra of 5CB in the aliphatic region with various decoupling sequences
13C NMR spectra of CH, CH2, and CH3 under the 32PPM and TPPM decoupling pulse sequences

His deep insights into nuclear dipole-dipole interactions brought methods like ‘adiabatic cross-polarization’ and ‘uniform saturation’ into the world.

 

NMR Molecular Photography

Anatoly’s demonstrated that one can encode bits of information on a single molecule. The figure shows a pixelated image, which was encoded in the nuclear spins of the molecule.

NMR Molecular Photography

 

Long-lived NMR echoes in solids

The same technique used for the molecular photography enabled to obtain high-resolution MRI images of objects with dipolar-broadened spectra, such as a liquid crystal and a pencil eraser.

5CB
Pencil Eraser
 

“Schrödinger cat” states and quantum amplifier

Anatoly had his unconventional approach to NMR quantum information processing. He demonstrated the so-called pseudo-pure ground and maximally entangled states on the largest and most complex systems at the moment. The figure shows the evidences of such states on a 7-qubit system.

1H and 13C spectra of [(a) and (a’)] the thermal equilibrium state; [(b) and (b’)] the state I0Z(|u><u|-|d><d|); [(c) and (c’)] the pseudopure state |↑>|u>; [(d) and (d’)] the pseudopure state |↓>|d> and [(e) and (e’)] numerically calculated spectra.
He devised schemes of amplified detection and measurement with a help of the maximally entangled states. The figure shows his idea of expanding the state of a single qubit into the state of N quits.

State expansion

He designed a quantum amplifier based on a 1D Ising chain. Here, one does not need any prepared entangled states.

Quantum amplifier made of a 1D Ising chain

Broad-band Suppression of Radiation Damping

Anatoly had an idea for broad-band suppression of radiation damping. With this simple technique, one can obtain spectra free from radiation damping of samples such as Vodka and gasoline.

Broad-band Radiation Damping Suppression: Spectrum of Pure Vodka

 

Controlling spontaneous emission by a sequence of phase kicks

Anatoly proposed models to study the measurement and decoherence processes in quantum systems. One model was an atom in a box interacting a photon.

Angular distribution of the probability for the emitted photon at t = 17.2 ns. Each dot represents an oscillator in the calculation; the solid line is sin2k).
Hamiltonian of an atom and field oscillators in the ‘single-photon’ subspace

 

Membrane Biophysics

The proposed mechanism of binding of a positively charged large molecule or particle to the interior of the membrane surface. (A). When the particle is in a conducting liquid, the electric field created by ionized groups extends only a short distance into the liquid. (B). When the particle comes in apposition with the membrane, its field penetrates into the membrane in the direction opposite to the field already present in the membrane. (C) Superposition of the field from the particle with the field in the membrane results in a decrease in the total field in the area indicated by the dotted line. The energy density within that area decreases to create an energetically favorable condition for particle binding. (courtesy of Dr. Michael Model)

 

Obituary in Physics Today:

https://physicstoday.scitation.org/do/10.1063/PT.6.4o.20180921a/full/